diff --git a/.gas-snapshot b/.gas-snapshot
index c07727f..ad998fb 100644
--- a/.gas-snapshot
+++ b/.gas-snapshot
@@ -1,69 +1,60 @@
-LibBloomTest:testLibBloomNoFalseNegatives(bytes32[],uint256,uint256) (runs: 1970, μ: 40231, ~: 34931)
-LibBloomTest:testLibBloomVaguelyAvoidsFalsePositives(uint256,uint8) (runs: 2048, μ: 1552760, ~: 23505)
+LibBloomTest:testLibBloomNoFalseNegatives(bytes32[],uint256,uint256) (runs: 2048, μ: 38135, ~: 30080)
+LibBloomTest:testLibBloomVaguelyAvoidsFalsePositives(uint256,uint8) (runs: 2048, μ: 1785796, ~: 13724)
 LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointers0() (gas: 421)
 LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointers1() (gas: 449)
-LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointers1Fail(bytes) (runs: 2022, μ: 5968, ~: 5949)
-LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointersConforming(bytes,uint256,bytes32) (runs: 2048, μ: 18014, ~: 15878)
-LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointersCorruptOffsetPointer(bytes,uint8,bytes32,uint8) (runs: 1349, μ: 23977, ~: 21571)
-LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointersCorruptOpsCount(bytes,uint8,bytes32,uint8) (runs: 1406, μ: 24561, ~: 22378)
-LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointersCorruptSourcesCount(bytes,uint8,bytes32,uint8) (runs: 1875, μ: 20024, ~: 18910)
-LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointersEndGarbage(bytes,bytes) (runs: 2023, μ: 17034, ~: 15942)
-LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointersHeaderTruncated(bytes,uint8,bytes32,uint256) (runs: 1472, μ: 25909, ~: 23510)
-LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointersInputsNotMonotonic(bytes,uint8,bytes32,uint256,uint256) (runs: 1482, μ: 28400, ~: 26010)
-LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointersOffsetsTruncated(bytes,uint8,uint256) (runs: 1755, μ: 10515, ~: 10554)
-LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointersOutputsNotMonotonic(bytes,uint8,bytes32,uint256,uint256) (runs: 1482, μ: 28390, ~: 26146)
-LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointersSourceTruncated(bytes,uint8,bytes32,uint8) (runs: 1406, μ: 24741, ~: 22550)
-LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointersTrailingOffsetBytes(bytes,bytes,uint8,bytes32) (runs: 1479, μ: 28945, ~: 25847)
+LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointers1Fail(bytes) (runs: 2048, μ: 5970, ~: 5949)
+LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointersConforming(bytes,uint256,bytes32) (runs: 2048, μ: 10604, ~: 8842)
+LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointersCorruptOffsetPointer(bytes,uint8,bytes32,uint8) (runs: 2048, μ: 16757, ~: 14890)
+LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointersCorruptOpsCount(bytes,uint8,bytes32,uint8) (runs: 2048, μ: 17474, ~: 15764)
+LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointersCorruptSourcesCount(bytes,uint8,bytes32,uint8) (runs: 2048, μ: 13079, ~: 12121)
+LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointersEndGarbage(bytes,bytes) (runs: 2048, μ: 12075, ~: 11058)
+LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointersHeaderTruncated(bytes,uint8,bytes32,uint256) (runs: 2048, μ: 18152, ~: 16236)
+LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointersInputsNotMonotonic(bytes,uint8,bytes32,uint256,uint256) (runs: 2048, μ: 19761, ~: 17786)
+LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointersOffsetsTruncated(bytes,uint8,uint256) (runs: 2048, μ: 7312, ~: 7454)
+LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointersOutputsNotMonotonic(bytes,uint8,bytes32,uint256,uint256) (runs: 2048, μ: 19751, ~: 17752)
+LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointersSourceTruncated(bytes,uint8,bytes32,uint8) (runs: 2048, μ: 17653, ~: 15934)
+LibBytecodeCheckNoOOBPointersTest:testCheckNoOOBPointersTrailingOffsetBytes(bytes,bytes,uint8,bytes32) (runs: 2048, μ: 21400, ~: 18933)
 LibBytecodeSourceCountTest:testSourceCount0() (gas: 343)
-LibBytecodeSourceCountTest:testSourceCount1(bytes) (runs: 2037, μ: 3611, ~: 3608)
+LibBytecodeSourceCountTest:testSourceCount1(bytes) (runs: 2048, μ: 3612, ~: 3608)
 LibBytecodeSourceCountTest:testSourceCountReference(bytes) (runs: 2048, μ: 827, ~: 824)
-LibBytecodeSourceInputsOutputsTest:testSourceInputsOutputsAgainstSlow(bytes,uint256,uint256,bytes32) (runs: 1661, μ: 26341, ~: 22906)
-LibBytecodeSourceInputsOutputsTest:testSourceInputsOutputsIndexOutOfBounds(bytes,uint256,uint256,bytes32) (runs: 2048, μ: 23602, ~: 21047)
+LibBytecodeSourceInputsOutputsTest:testSourceInputsOutputsAgainstSlow(bytes,uint256,uint256,bytes32) (runs: 2048, μ: 16973, ~: 14633)
+LibBytecodeSourceInputsOutputsTest:testSourceInputsOutputsIndexOutOfBounds(bytes,uint256,uint256,bytes32) (runs: 2048, μ: 14549, ~: 12958)
 LibBytecodeSourceOpsCountTest:testSourceOpsCount() (gas: 2163)
-LibBytecodeSourceOpsCountTest:testSourceOpsCountAgainstSlow(bytes,uint256,uint256,bytes32) (runs: 1659, μ: 26295, ~: 22735)
-LibBytecodeSourceOpsCountTest:testSourceOpsCountIndexOutOfBounds(bytes,uint256,uint256,bytes32) (runs: 2048, μ: 23606, ~: 21108)
-LibBytecodeSourcePointerTest:testSourcePointerAgainstSlow(bytes,uint256,uint256,bytes32) (runs: 1640, μ: 26289, ~: 22593)
+LibBytecodeSourceOpsCountTest:testSourceOpsCountAgainstSlow(bytes,uint256,uint256,bytes32) (runs: 2048, μ: 16795, ~: 14466)
+LibBytecodeSourceOpsCountTest:testSourceOpsCountIndexOutOfBounds(bytes,uint256,uint256,bytes32) (runs: 2048, μ: 14448, ~: 12984)
+LibBytecodeSourcePointerTest:testSourcePointerAgainstSlow(bytes,uint256,uint256,bytes32) (runs: 2048, μ: 16649, ~: 14320)
 LibBytecodeSourcePointerTest:testSourcePointerEmpty0(uint256) (runs: 2048, μ: 5407, ~: 5407)
 LibBytecodeSourcePointerTest:testSourcePointerEmpty1(uint256) (runs: 2048, μ: 5486, ~: 5486)
-LibBytecodeSourcePointerTest:testSourcePointerIndexOutOfBounds(bytes,uint256,uint256,bytes32) (runs: 2048, μ: 23572, ~: 21102)
+LibBytecodeSourcePointerTest:testSourcePointerIndexOutOfBounds(bytes,uint256,uint256,bytes32) (runs: 2048, μ: 14494, ~: 13076)
 LibBytecodeSourceRelativeOffsetTest:testSourceRelativeOffsetHappy() (gas: 1215)
 LibBytecodeSourceRelativeOffsetTest:testSourceRelativeOffsetIndexError() (gas: 85666)
-LibBytecodeSourceRelativeOffsetTest:testSourceRelativeOffsetReference(bytes,uint256,uint256,bytes32) (runs: 1652, μ: 25544, ~: 22042)
-LibBytecodeSourceStackAllocationTest:testSourceStackAllocationAgainstSlow(bytes,uint256,uint256,bytes32) (runs: 1630, μ: 26518, ~: 23055)
-LibBytecodeSourceStackAllocationTest:testSourceStackAllocationIndexOutOfBounds(bytes,uint256,uint256,bytes32) (runs: 2048, μ: 23528, ~: 21105)
+LibBytecodeSourceRelativeOffsetTest:testSourceRelativeOffsetReference(bytes,uint256,uint256,bytes32) (runs: 2048, μ: 16124, ~: 13660)
+LibBytecodeSourceStackAllocationTest:testSourceStackAllocationAgainstSlow(bytes,uint256,uint256,bytes32) (runs: 2048, μ: 16835, ~: 14408)
+LibBytecodeSourceStackAllocationTest:testSourceStackAllocationIndexOutOfBounds(bytes,uint256,uint256,bytes32) (runs: 2048, μ: 14456, ~: 12875)
 LibContextHashTest:testFuzzHash0() (gas: 3537)
 LibContextHashTest:testHash(uint256) (runs: 2048, μ: 279, ~: 279)
 LibContextHashTest:testHashGas0() (gas: 206)
-LibContextHashTest:testSignedContextArrayHashReferenceImplementation((address,bytes32[],bytes)[]) (runs: 100, μ: 2614880, ~: 2346946)
+LibContextHashTest:testSignedContextArrayHashReferenceImplementation((address,bytes32[],bytes)[]) (runs: 100, μ: 2424301, ~: 1983631)
 LibContextHashTest:testSignedContextArrayHashReferenceImplementation0() (gas: 2172)
 LibContextHashTest:testSignedContextHashEncodeGas0() (gas: 1441)
 LibContextHashTest:testSignedContextHashGas0() (gas: 824)
-LibContextHashTest:testSignedContextHashReferenceImplementation((address,bytes32[],bytes)) (runs: 100, μ: 13598, ~: 13190)
+LibContextHashTest:testSignedContextHashReferenceImplementation((address,bytes32[],bytes)) (runs: 100, μ: 13641, ~: 13569)
 LibContextTest:testBase() (gas: 611)
 LibContextTest:testBuild0() (gas: 5010)
 LibContextTest:testBuildGas0() (gas: 953)
 LibContextTest:testBuildStructureReferenceImplementation(bytes32[][]) (runs: 100, μ: 4645490, ~: 4797429)
-LibDeployerDiscoverableTest:testTouchDeployerV4Mock() (gas: 175612)
-LibEncodedDispatchTest:testRoundTrip(address,uint256,uint16) (runs: 2048, μ: 4406, ~: 4681)
-LibEvaluableTest:testEvaluableV2HashDifferent((address,address,address),(address,address,address)) (runs: 2048, μ: 4233, ~: 4233)
-LibEvaluableTest:testEvaluableV2HashGas0() (gas: 295)
-LibEvaluableTest:testEvaluableV2HashGasSlow0() (gas: 580)
-LibEvaluableTest:testEvaluableV2HashSame((address,address,address)) (runs: 2048, μ: 1003, ~: 1003)
-LibEvaluableTest:testEvaluableV2HashSensitivity((address,address,address),(address,address,address)) (runs: 2045, μ: 5990, ~: 5990)
-LibEvaluableTest:testEvaluableV2KnownHash() (gas: 353)
-LibEvaluableTest:testEvaluableV2ReferenceImplementation((address,address,address)) (runs: 2048, μ: 1066, ~: 1066)
-LibEvaluableTest:testEvaluableV3BytecodeLengthSensitivity() (gas: 898)
-LibEvaluableTest:testEvaluableV3HashDifferent((address,address,bytes),(address,address,bytes)) (runs: 2048, μ: 5185, ~: 5183)
-LibEvaluableTest:testEvaluableV3HashGas0() (gas: 429)
-LibEvaluableTest:testEvaluableV3HashGasSlow0() (gas: 758)
-LibEvaluableTest:testEvaluableV3HashSame((address,address,bytes)) (runs: 2048, μ: 1599, ~: 1588)
-LibEvaluableTest:testEvaluableV3HashSensitivity((address,address,bytes),(address,address,bytes)) (runs: 2044, μ: 8320, ~: 8293)
-LibEvaluableTest:testEvaluableV3KnownHash() (gas: 602)
-LibEvaluableTest:testEvaluableV3ReferenceImplementation((address,address,bytes)) (runs: 2048, μ: 1704, ~: 1693)
-LibGenParseMetaBuildMetaTest:testBuildMeta((bytes32,string)[]) (runs: 745, μ: 3674384, ~: 2813977)
-LibGenParseMetaBuildMetaTest:testRoundMetaExpanderDeeper((bytes32,string)[],uint8,bytes32) (runs: 366, μ: 6652382, ~: 6359523)
-LibGenParseMetaBuildMetaTest:testRoundMetaExpanderShallow((bytes32,string)[],uint8,bytes32) (runs: 715, μ: 3521627, ~: 3137421)
-LibGenParseMetaFindExpanderTest:testFindExpanderSmall((bytes32,string)[]) (runs: 254, μ: 41946, ~: 33181)
+LibEvaluableTest:testEvaluableV4BytecodeLengthSensitivity() (gas: 897)
+LibEvaluableTest:testEvaluableV4HashDifferent((address,address,bytes),(address,address,bytes)) (runs: 2048, μ: 5148, ~: 5149)
+LibEvaluableTest:testEvaluableV4HashGas0() (gas: 429)
+LibEvaluableTest:testEvaluableV4HashGasSlow0() (gas: 768)
+LibEvaluableTest:testEvaluableV4HashSame((address,address,bytes)) (runs: 2048, μ: 1565, ~: 1554)
+LibEvaluableTest:testEvaluableV4HashSensitivity((address,address,bytes),(address,address,bytes)) (runs: 2048, μ: 8278, ~: 8263)
+LibEvaluableTest:testEvaluableV4KnownHash() (gas: 580)
+LibEvaluableTest:testEvaluableV4ReferenceImplementation((address,address,bytes)) (runs: 2048, μ: 1693, ~: 1682)
+LibGenParseMetaBuildMetaTest:testBuildMeta((bytes32,string)[]) (runs: 2048, μ: 3700890, ~: 3857085)
+LibGenParseMetaBuildMetaTest:testRoundMetaExpanderDeeper((bytes32,string)[],uint8,bytes32) (runs: 2048, μ: 6807238, ~: 6710253)
+LibGenParseMetaBuildMetaTest:testRoundMetaExpanderShallow((bytes32,string)[],uint8,bytes32) (runs: 2048, μ: 3776067, ~: 4027823)
+LibGenParseMetaFindExpanderTest:testFindExpanderSmall((bytes32,string)[]) (runs: 2048, μ: 41282, ~: 31299)
 LibNamespaceTest:testQualifyNamespaceGas0(uint256,address) (runs: 2048, μ: 359, ~: 359)
 LibNamespaceTest:testQualifyNamespaceGasSlow0(uint256,address) (runs: 2048, μ: 566, ~: 566)
 LibNamespaceTest:testQualifyNamespaceReferenceImplementation(uint256,address) (runs: 2048, μ: 722, ~: 722)
diff --git a/src/error/ErrBytecode.sol b/src/error/ErrBytecode.sol
index 30313a5..08590de 100644
--- a/src/error/ErrBytecode.sol
+++ b/src/error/ErrBytecode.sol
@@ -2,9 +2,6 @@
 // SPDX-FileCopyrightText: Copyright (c) 2020 Rain Open Source Software Ltd
 pragma solidity ^0.8.25;
 
-/// @dev Workaround for https://github.com/foundry-rs/foundry/issues/6572
-contract ErrBytecode {}
-
 /// Thrown when a bytecode source index is out of bounds.
 /// @param sourceIndex The source index that was out of bounds.
 /// @param bytecode The bytecode that was inspected.
diff --git a/src/error/ErrExtern.sol b/src/error/ErrExtern.sol
index c5fdecf..017358f 100644
--- a/src/error/ErrExtern.sol
+++ b/src/error/ErrExtern.sol
@@ -2,9 +2,6 @@
 // SPDX-FileCopyrightText: Copyright (c) 2020 Rain Open Source Software Ltd
 pragma solidity ^0.8.25;
 
-/// @dev Workaround for https://github.com/foundry-rs/foundry/issues/6572
-contract ErrExtern {}
-
 /// Thrown when the extern interface is not supported.
 error NotAnExternContract(address extern);
 
diff --git a/src/interface/unstable/IInterpreterCallerV4.sol b/src/interface/IInterpreterCallerV4.sol
similarity index 95%
rename from src/interface/unstable/IInterpreterCallerV4.sol
rename to src/interface/IInterpreterCallerV4.sol
index ddb5309..66c88f0 100644
--- a/src/interface/unstable/IInterpreterCallerV4.sol
+++ b/src/interface/IInterpreterCallerV4.sol
@@ -4,7 +4,7 @@ pragma solidity ^0.8.18;
 
 // Exported for convenience.
 //forge-lint: disable-next-line(unused-import)
-import {IParserV2} from "../IParserV2.sol";
+import {IParserV2} from "./IParserV2.sol";
 import {IInterpreterStoreV3} from "./IInterpreterStoreV3.sol";
 import {IInterpreterV4} from "./IInterpreterV4.sol";
 import {
@@ -15,7 +15,7 @@ import {
     SIGNED_CONTEXT_SIGNER_OFFSET,
     SIGNED_CONTEXT_CONTEXT_OFFSET,
     SIGNED_CONTEXT_SIGNATURE_OFFSET
-} from "../IInterpreterCallerV3.sol";
+} from "./deprecated/v2/IInterpreterCallerV3.sol";
 
 //forge-lint: disable-end
 
diff --git a/src/interface/unstable/IInterpreterExternV4.sol b/src/interface/IInterpreterExternV4.sol
similarity index 100%
rename from src/interface/unstable/IInterpreterExternV4.sol
rename to src/interface/IInterpreterExternV4.sol
diff --git a/src/interface/unstable/IInterpreterStoreV3.sol b/src/interface/IInterpreterStoreV3.sol
similarity index 98%
rename from src/interface/unstable/IInterpreterStoreV3.sol
rename to src/interface/IInterpreterStoreV3.sol
index 1ef7e28..fc56868 100644
--- a/src/interface/unstable/IInterpreterStoreV3.sol
+++ b/src/interface/IInterpreterStoreV3.sol
@@ -4,7 +4,7 @@ pragma solidity ^0.8.18;
 
 // Exported for convenience.
 //forge-lint: disable-next-line(unused-import)
-import {StateNamespace, FullyQualifiedNamespace, NO_STORE} from "../IInterpreterStoreV2.sol";
+import {StateNamespace, FullyQualifiedNamespace, NO_STORE} from "./deprecated/v2/IInterpreterStoreV2.sol";
 
 /// @title IInterpreterStoreV3
 /// @notice Tracks state changes on behalf of an interpreter. A single store can
diff --git a/src/interface/unstable/IInterpreterV4.sol b/src/interface/IInterpreterV4.sol
similarity index 98%
rename from src/interface/unstable/IInterpreterV4.sol
rename to src/interface/IInterpreterV4.sol
index b1279f6..5571bb1 100644
--- a/src/interface/unstable/IInterpreterV4.sol
+++ b/src/interface/IInterpreterV4.sol
@@ -33,7 +33,7 @@ import {
     // Exported for convenience.
     //forge-lint: disable-next-line(unused-import)
     OPCODE_STACK
-} from "../IInterpreterV3.sol";
+} from "./deprecated/v2/IInterpreterV3.sol";
 import {IInterpreterStoreV3} from "./IInterpreterStoreV3.sol";
 
 type OperandV2 is bytes32;
diff --git a/src/interface/IParserV2.sol b/src/interface/IParserV2.sol
index 155c383..08b1b5b 100644
--- a/src/interface/IParserV2.sol
+++ b/src/interface/IParserV2.sol
@@ -4,7 +4,7 @@ pragma solidity ^0.8.18;
 
 // Reexport AuthoringMetaV2 for downstream use.
 //forge-lint: disable-next-line(unused-import)
-import {AuthoringMetaV2} from "./deprecated/IParserV1.sol";
+import {AuthoringMetaV2} from "./deprecated/v1/IParserV1.sol";
 
 interface IParserV2 {
     function parse2(bytes calldata data) external view returns (bytes calldata bytecode);
diff --git a/src/interface/unstable/ISubParserV4.sol b/src/interface/ISubParserV4.sol
similarity index 98%
rename from src/interface/unstable/ISubParserV4.sol
rename to src/interface/ISubParserV4.sol
index 3c7b78f..cea444c 100644
--- a/src/interface/unstable/ISubParserV4.sol
+++ b/src/interface/ISubParserV4.sol
@@ -4,7 +4,7 @@ pragma solidity ^0.8.18;
 
 // Reexports for implementations to use.
 //forge-lint: disable-next-line(unused-import)
-import {AuthoringMetaV2} from "../ISubParserV3.sol";
+import {AuthoringMetaV2} from "./deprecated/v2/ISubParserV3.sol";
 //forge-lint: disable-next-line(unused-import)
 import {OperandV2} from "./IInterpreterV4.sol";
 
diff --git a/src/interface/deprecated/IDebugExpressionDeployerV1.sol b/src/interface/deprecated/v1/IDebugExpressionDeployerV1.sol
similarity index 100%
rename from src/interface/deprecated/IDebugExpressionDeployerV1.sol
rename to src/interface/deprecated/v1/IDebugExpressionDeployerV1.sol
diff --git a/src/interface/deprecated/IDebugExpressionDeployerV2.sol b/src/interface/deprecated/v1/IDebugExpressionDeployerV2.sol
similarity index 100%
rename from src/interface/deprecated/IDebugExpressionDeployerV2.sol
rename to src/interface/deprecated/v1/IDebugExpressionDeployerV2.sol
diff --git a/src/interface/deprecated/IDebugInterpreterV1.sol b/src/interface/deprecated/v1/IDebugInterpreterV1.sol
similarity index 100%
rename from src/interface/deprecated/IDebugInterpreterV1.sol
rename to src/interface/deprecated/v1/IDebugInterpreterV1.sol
diff --git a/src/interface/deprecated/IDebugInterpreterV2.sol b/src/interface/deprecated/v1/IDebugInterpreterV2.sol
similarity index 100%
rename from src/interface/deprecated/IDebugInterpreterV2.sol
rename to src/interface/deprecated/v1/IDebugInterpreterV2.sol
diff --git a/src/interface/deprecated/IExpressionDeployerV1.sol b/src/interface/deprecated/v1/IExpressionDeployerV1.sol
similarity index 100%
rename from src/interface/deprecated/IExpressionDeployerV1.sol
rename to src/interface/deprecated/v1/IExpressionDeployerV1.sol
diff --git a/src/interface/deprecated/IExpressionDeployerV2.sol b/src/interface/deprecated/v1/IExpressionDeployerV2.sol
similarity index 100%
rename from src/interface/deprecated/IExpressionDeployerV2.sol
rename to src/interface/deprecated/v1/IExpressionDeployerV2.sol
diff --git a/src/interface/deprecated/IExpressionDeployerV3.sol b/src/interface/deprecated/v1/IExpressionDeployerV3.sol
similarity index 99%
rename from src/interface/deprecated/IExpressionDeployerV3.sol
rename to src/interface/deprecated/v1/IExpressionDeployerV3.sol
index b43d921..bb6f06a 100644
--- a/src/interface/deprecated/IExpressionDeployerV3.sol
+++ b/src/interface/deprecated/v1/IExpressionDeployerV3.sol
@@ -2,7 +2,7 @@
 // SPDX-FileCopyrightText: Copyright (c) 2020 Rain Open Source Software Ltd
 pragma solidity ^0.8.18;
 
-import {IInterpreterStoreV2} from "../IInterpreterStoreV2.sol";
+import {IInterpreterStoreV2} from "../v2/IInterpreterStoreV2.sol";
 import {IInterpreterV2} from "./IInterpreterV2.sol";
 
 string constant IERC1820_NAME_IEXPRESSION_DEPLOYER_V3 = "IExpressionDeployerV3";
diff --git a/src/interface/deprecated/IExpressionDeployerV4.sol b/src/interface/deprecated/v1/IExpressionDeployerV4.sol
similarity index 99%
rename from src/interface/deprecated/IExpressionDeployerV4.sol
rename to src/interface/deprecated/v1/IExpressionDeployerV4.sol
index bfecc78..bf2c864 100644
--- a/src/interface/deprecated/IExpressionDeployerV4.sol
+++ b/src/interface/deprecated/v1/IExpressionDeployerV4.sol
@@ -2,7 +2,7 @@
 // SPDX-FileCopyrightText: Copyright (c) 2020 Rain Open Source Software Ltd
 pragma solidity ^0.8.18;
 
-import {IInterpreterStoreV2} from "../IInterpreterStoreV2.sol";
+import {IInterpreterStoreV2} from "../v2/IInterpreterStoreV2.sol";
 import {IInterpreterV2} from "./IInterpreterV2.sol";
 
 string constant IERC1820_NAME_IEXPRESSION_DEPLOYER_V4 = "IExpressionDeployerV4";
diff --git a/src/interface/deprecated/IInterpreterCallerV1.sol b/src/interface/deprecated/v1/IInterpreterCallerV1.sol
similarity index 100%
rename from src/interface/deprecated/IInterpreterCallerV1.sol
rename to src/interface/deprecated/v1/IInterpreterCallerV1.sol
diff --git a/src/interface/deprecated/IInterpreterCallerV2.sol b/src/interface/deprecated/v1/IInterpreterCallerV2.sol
similarity index 98%
rename from src/interface/deprecated/IInterpreterCallerV2.sol
rename to src/interface/deprecated/v1/IInterpreterCallerV2.sol
index 3e1b0bc..50fae36 100644
--- a/src/interface/deprecated/IInterpreterCallerV2.sol
+++ b/src/interface/deprecated/v1/IInterpreterCallerV2.sol
@@ -3,7 +3,7 @@
 pragma solidity ^0.8.18;
 
 import {IExpressionDeployerV3} from "./IExpressionDeployerV3.sol";
-import {IInterpreterStoreV2} from "../IInterpreterStoreV2.sol";
+import {IInterpreterStoreV2} from "../v2/IInterpreterStoreV2.sol";
 import {IInterpreterV2} from "./IInterpreterV2.sol";
 
 /// Standard struct that can be embedded in ABIs in a consistent format for
diff --git a/src/interface/deprecated/IInterpreterExternV1.sol b/src/interface/deprecated/v1/IInterpreterExternV1.sol
similarity index 100%
rename from src/interface/deprecated/IInterpreterExternV1.sol
rename to src/interface/deprecated/v1/IInterpreterExternV1.sol
diff --git a/src/interface/deprecated/IInterpreterExternV2.sol b/src/interface/deprecated/v1/IInterpreterExternV2.sol
similarity index 100%
rename from src/interface/deprecated/IInterpreterExternV2.sol
rename to src/interface/deprecated/v1/IInterpreterExternV2.sol
diff --git a/src/interface/deprecated/IInterpreterStoreV1.sol b/src/interface/deprecated/v1/IInterpreterStoreV1.sol
similarity index 100%
rename from src/interface/deprecated/IInterpreterStoreV1.sol
rename to src/interface/deprecated/v1/IInterpreterStoreV1.sol
diff --git a/src/interface/deprecated/IInterpreterV1.sol b/src/interface/deprecated/v1/IInterpreterV1.sol
similarity index 100%
rename from src/interface/deprecated/IInterpreterV1.sol
rename to src/interface/deprecated/v1/IInterpreterV1.sol
diff --git a/src/interface/deprecated/IInterpreterV2.sol b/src/interface/deprecated/v1/IInterpreterV2.sol
similarity index 99%
rename from src/interface/deprecated/IInterpreterV2.sol
rename to src/interface/deprecated/v1/IInterpreterV2.sol
index d874e7c..d0c1992 100644
--- a/src/interface/deprecated/IInterpreterV2.sol
+++ b/src/interface/deprecated/v1/IInterpreterV2.sol
@@ -5,7 +5,7 @@ pragma solidity ^0.8.18;
 // Exported for convenience.
 //forge-lint: disable-next-line(unused-import)
 import {EncodedDispatch, StateNamespace, Operand, DEFAULT_STATE_NAMESPACE} from "./IInterpreterV1.sol";
-import {FullyQualifiedNamespace, IInterpreterStoreV2} from "../IInterpreterStoreV2.sol";
+import {FullyQualifiedNamespace, IInterpreterStoreV2} from "../v2/IInterpreterStoreV2.sol";
 
 /// @dev For maximum compatibility with external contracts, the `IInterpreterV2`
 /// should implement an opcode that reads from the stack by index as opcode `0`.
diff --git a/src/interface/deprecated/IParserV1.sol b/src/interface/deprecated/v1/IParserV1.sol
similarity index 100%
rename from src/interface/deprecated/IParserV1.sol
rename to src/interface/deprecated/v1/IParserV1.sol
diff --git a/src/interface/deprecated/IParserV1View.sol b/src/interface/deprecated/v1/IParserV1View.sol
similarity index 100%
rename from src/interface/deprecated/IParserV1View.sol
rename to src/interface/deprecated/v1/IParserV1View.sol
diff --git a/src/interface/deprecated/ISubParserV1.sol b/src/interface/deprecated/v1/ISubParserV1.sol
similarity index 100%
rename from src/interface/deprecated/ISubParserV1.sol
rename to src/interface/deprecated/v1/ISubParserV1.sol
diff --git a/src/interface/deprecated/ISubParserV2.sol b/src/interface/deprecated/v1/ISubParserV2.sol
similarity index 100%
rename from src/interface/deprecated/ISubParserV2.sol
rename to src/interface/deprecated/v1/ISubParserV2.sol
diff --git a/src/interface/IInterpreterCallerV3.sol b/src/interface/deprecated/v2/IInterpreterCallerV3.sol
similarity index 95%
rename from src/interface/IInterpreterCallerV3.sol
rename to src/interface/deprecated/v2/IInterpreterCallerV3.sol
index 7acf436..8d3c98f 100644
--- a/src/interface/IInterpreterCallerV3.sol
+++ b/src/interface/deprecated/v2/IInterpreterCallerV3.sol
@@ -4,7 +4,7 @@ pragma solidity ^0.8.18;
 
 // Exported for convenience.
 //forge-lint: disable-next-line(unused-import)
-import {IParserV2} from "./IParserV2.sol";
+import {IParserV2} from "../../IParserV2.sol";
 import {IInterpreterStoreV2} from "./IInterpreterStoreV2.sol";
 import {IInterpreterV3} from "./IInterpreterV3.sol";
 import {
@@ -15,7 +15,7 @@ import {
     SIGNED_CONTEXT_SIGNER_OFFSET,
     SIGNED_CONTEXT_CONTEXT_OFFSET,
     SIGNED_CONTEXT_SIGNATURE_OFFSET
-} from "./deprecated/IInterpreterCallerV2.sol";
+} from "../v1/IInterpreterCallerV2.sol";
 
 //forge-lint: disable-end
 
diff --git a/src/interface/IInterpreterExternV3.sol b/src/interface/deprecated/v2/IInterpreterExternV3.sol
similarity index 95%
rename from src/interface/IInterpreterExternV3.sol
rename to src/interface/deprecated/v2/IInterpreterExternV3.sol
index 3680441..0c4cb48 100644
--- a/src/interface/IInterpreterExternV3.sol
+++ b/src/interface/deprecated/v2/IInterpreterExternV3.sol
@@ -4,7 +4,7 @@ pragma solidity ^0.8.18;
 
 // Exported for convenience.
 //forge-lint: disable-next-line(unused-import)
-import {EncodedExternDispatch, ExternDispatch} from "./deprecated/IInterpreterExternV2.sol";
+import {EncodedExternDispatch, ExternDispatch} from "../v1/IInterpreterExternV2.sol";
 
 /// @title IInterpreterExternV3
 /// Handle a single dispatch from some calling contract with an array of
diff --git a/src/interface/IInterpreterStoreV2.sol b/src/interface/deprecated/v2/IInterpreterStoreV2.sol
similarity index 98%
rename from src/interface/IInterpreterStoreV2.sol
rename to src/interface/deprecated/v2/IInterpreterStoreV2.sol
index 7f0db31..2798c1f 100644
--- a/src/interface/IInterpreterStoreV2.sol
+++ b/src/interface/deprecated/v2/IInterpreterStoreV2.sol
@@ -4,7 +4,7 @@ pragma solidity ^0.8.18;
 
 // Exported for convenience.
 //forge-lint: disable-next-line(unused-import)
-import {StateNamespace, FullyQualifiedNamespace, NO_STORE} from "./deprecated/IInterpreterStoreV1.sol";
+import {StateNamespace, FullyQualifiedNamespace, NO_STORE} from "../v1/IInterpreterStoreV1.sol";
 
 /// @title IInterpreterStoreV2
 /// @notice Tracks state changes on behalf of an interpreter. A single store can
diff --git a/src/interface/IInterpreterV3.sol b/src/interface/deprecated/v2/IInterpreterV3.sol
similarity index 97%
rename from src/interface/IInterpreterV3.sol
rename to src/interface/deprecated/v2/IInterpreterV3.sol
index 580c597..4308e93 100644
--- a/src/interface/IInterpreterV3.sol
+++ b/src/interface/deprecated/v2/IInterpreterV3.sol
@@ -38,7 +38,7 @@ import {
     // Exported for convenience.
     //forge-lint: disable-next-line(unused-import)
     OPCODE_STACK
-} from "./deprecated/IInterpreterV2.sol";
+} from "../v1/IInterpreterV2.sol";
 
 interface IInterpreterV3 {
     function functionPointers() external view returns (bytes calldata);
diff --git a/src/interface/IParserPragmaV1.sol b/src/interface/deprecated/v2/IParserPragmaV1.sol
similarity index 100%
rename from src/interface/IParserPragmaV1.sol
rename to src/interface/deprecated/v2/IParserPragmaV1.sol
diff --git a/src/interface/ISubParserV3.sol b/src/interface/deprecated/v2/ISubParserV3.sol
similarity index 97%
rename from src/interface/ISubParserV3.sol
rename to src/interface/deprecated/v2/ISubParserV3.sol
index 5d769bc..7a65fae 100644
--- a/src/interface/ISubParserV3.sol
+++ b/src/interface/deprecated/v2/ISubParserV3.sol
@@ -4,13 +4,13 @@ pragma solidity ^0.8.18;
 
 // Reexports for implementations to use.
 //forge-lint: disable-next-line(unused-import)
-import {AuthoringMetaV2} from "./deprecated/IParserV1.sol";
+import {AuthoringMetaV2} from "../v1/IParserV1.sol";
 // Exported for convenience.
 //forge-lint: disable-next-line(unused-import)
-import {Operand} from "./deprecated/IInterpreterV2.sol";
+import {Operand} from "../v1/IInterpreterV2.sol";
 // Exported for convenience.
 //forge-lint: disable-next-line(unused-import)
-import {COMPATIBILITY_V2, COMPATIBILITY_V3, COMPATIBILITY_V4} from "./deprecated/ISubParserV2.sol";
+import {COMPATIBILITY_V2, COMPATIBILITY_V3, COMPATIBILITY_V4} from "../v1/ISubParserV2.sol";
 
 /// @dev A compatibility version for the subparser interface.
 ///
diff --git a/src/lib/caller/LibContext.sol b/src/lib/caller/LibContext.sol
index d28b3bf..5e1fc69 100644
--- a/src/lib/caller/LibContext.sol
+++ b/src/lib/caller/LibContext.sol
@@ -13,15 +13,24 @@ import {
     SIGNED_CONTEXT_SIGNER_OFFSET,
     SIGNED_CONTEXT_SIGNATURE_OFFSET,
     SIGNED_CONTEXT_CONTEXT_OFFSET
-} from "../../interface/IInterpreterCallerV3.sol";
+} from "../../interface/IInterpreterCallerV4.sol";
 
 /// Thrown when the ith signature from a list of signed contexts is invalid.
+/// @param i The index of the invalid signature in the list of signed contexts.
 error InvalidSignature(uint256 i);
 
+/// @dev CONTEXT_BASE_COLUMN and CONTEXT_BASE_ROWS are the dimensions of the base
+/// context provided by `LibContext.base()`. These constants are not required to
+/// use the base context but are provided for convenience when working with it.
 uint256 constant CONTEXT_BASE_COLUMN = 0;
+/// @dev CONTEXT_BASE_ROWS is the number of rows in the base context, which is
+/// always 2 for the `msg.sender` and address of the calling contract.
 uint256 constant CONTEXT_BASE_ROWS = 2;
 
+/// @dev The row index of the `msg.sender` in the base context.
 uint256 constant CONTEXT_BASE_ROW_SENDER = 0;
+/// @dev The row index of the address of the calling contract in the base
+/// context.
 uint256 constant CONTEXT_BASE_ROW_CALLING_CONTRACT = 1;
 
 /// @title LibContext
diff --git a/src/lib/caller/LibEvaluable.sol b/src/lib/caller/LibEvaluable.sol
index 3624aca..810061a 100644
--- a/src/lib/caller/LibEvaluable.sol
+++ b/src/lib/caller/LibEvaluable.sol
@@ -5,40 +5,22 @@ pragma solidity ^0.8.25;
 /// Export dispair interfaces for convenience downstream.
 // Exported for convenience.
 //forge-lint: disable-next-line(unused-import)
-import {IInterpreterStoreV2} from "../../interface/IInterpreterStoreV2.sol";
-// Exported for convenience.
-//forge-lint: disable-next-line(unused-import)
-import {IInterpreterV2} from "../../interface/deprecated/IInterpreterV2.sol";
-import {EvaluableV2} from "../../interface/deprecated/IInterpreterCallerV2.sol";
+import {IInterpreterStoreV3} from "../../interface/IInterpreterStoreV3.sol";
 
-import {EvaluableV3} from "../../interface/IInterpreterCallerV3.sol";
+import {EvaluableV4} from "../../interface/IInterpreterCallerV4.sol";
 
 /// @title LibEvaluable
 /// @notice Common logic to provide consistent implementations of common tasks
 /// that could be arbitrarily/ambiguously implemented, but work much better if
 /// consistently implemented.
 library LibEvaluable {
-    /// Hashes an `EvaluableV2`, ostensibly so that only the hash need be stored,
-    /// thus only storing a single `uint256` instead of 3x `uint160`.
-    /// @param evaluable The evaluable to hash.
-    /// @return evaluableHash Standard hash of the evaluable.
-    function hash(EvaluableV2 memory evaluable) internal pure returns (bytes32 evaluableHash) {
-        // `Evaluable` does NOT contain any dynamic types so it is safe to encode
-        // packed for hashing, and is preferable due to the smaller/simpler
-        // in-memory structure. It also makes it easier to replicate the logic
-        // offchain as a simple concatenation of bytes.
-        assembly ("memory-safe") {
-            evaluableHash := keccak256(evaluable, 0x60)
-        }
-    }
-
-    /// Hashes an `EvaluableV3`, ostensibly so that only the hash need be stored,
+    /// Hashes an `EvaluableV4`, ostensibly so that only the hash need be stored,
     /// thus only storing a single `bytes32` instead of 2x `address` and an
     /// arbitrary length `bytes`.
     /// https://github.com/rainlanguage/rain.lib.hash?tab=readme-ov-file#the-pattern
     /// @param evaluable The evaluable to hash.
     /// @return evaluableHash Standard hash of the evaluable.
-    function hash(EvaluableV3 memory evaluable) internal pure returns (bytes32) {
+    function hash(EvaluableV4 memory evaluable) internal pure returns (bytes32) {
         bytes memory bytecode = evaluable.bytecode;
         bytes32 evaluableHash;
         assembly ("memory-safe") {
diff --git a/src/lib/codegen/LibGenParseMeta.sol b/src/lib/codegen/LibGenParseMeta.sol
index 0daa2f4..c75fefb 100644
--- a/src/lib/codegen/LibGenParseMeta.sol
+++ b/src/lib/codegen/LibGenParseMeta.sol
@@ -20,7 +20,32 @@ uint256 constant META_ITEM_MASK = (1 << META_ITEM_SIZE) - 1;
 /// @dev For metadata builder.
 error DuplicateFingerprint();
 
+/// @title LibGenParseMeta
+/// @notice Library for building parse meta from authoring meta, and generating
+/// constant strings for the parse meta to be used in generated code. The parse
+/// meta is a bytes array that is used to lookup word definitions. The parse meta
+/// is built from the authoring meta, which is an array of `AuthoringMetaV2` that
+/// contains the word and its corresponding opcode index. The parse meta is
+/// structured in a way that allows for efficient lookups of word definitions
+/// using bloom filters and fingerprints. The library provides functions to find
+/// the best expander for a given set of authoring meta, build the parse meta
+/// from the authoring meta and build depth, and generate a constant string for
+/// the parse meta with a comment describing its structure. The main purpose of
+/// this library is to optimize the size of the parse meta while maintaining
+/// efficient lookups, which is important for the performance of the interpreter.
 library LibGenParseMeta {
+    /// @dev Finds the best expander for a given set of authoring meta. The best
+    /// expander is the one that produces the densest bloom filter at each depth,
+    /// which minimizes the number of items that need to be checked for each
+    /// lookup. The function returns the best seed, the corresponding expansion,
+    /// and the remaining authoring meta that could not be expanded with this
+    /// seed. The remaining authoring meta can then be used to find the next best
+    /// expander until all authoring meta has been expanded.
+    /// @param metas The authoring meta to find the best expander for.
+    /// @return bestSeed The best seed for the given authoring meta.
+    /// @return bestExpansion The corresponding expansion for the best seed.
+    /// @return remaining The remaining authoring meta that could not be expanded
+    /// with the best seed.
     function findBestExpander(AuthoringMetaV2[] memory metas)
         internal
         pure
@@ -72,6 +97,32 @@ library LibGenParseMeta {
         }
     }
 
+    /// @dev Builds the parse meta from the authoring meta and build depth. The
+    /// parse meta is a bytes array with the following structure:
+    /// - 1 byte: The depth of the bloom filters
+    /// - 1 byte: The hashing seed
+    /// - The bloom filters, each is 32 bytes long, one for each build depth
+    /// - All the items for each word, each is 4 bytes long. Each item's first
+    ///   byte is its opcode index, the remaining 3 bytes are the word
+    ///   fingerprint.
+    /// The parse meta is used to lookup word definitions. To do a lookup, the
+    /// word is hashed with the seed, then the first byte of the hash is compared
+    /// against the bloom filter. If there is a hit then we count the number of
+    /// 1 bits in the bloom filter up to this item's 1 bit. We then treat this
+    /// as the index of the item in the items array. We then compare the word
+    /// fingerprint against the fingerprint of the item at this index. If the
+    /// fingerprints equal then we have a match, else we increment the seed and
+    /// try again with the next bloom filter, offsetting all the indexes by the
+    /// total bit count of the previous bloom filter. If we reach the end of the
+    /// bloom filters then we have a miss.
+    /// @param authoringMeta The authoring meta to build the parse meta from.
+    /// @param maxDepth The maximum depth of the bloom filters to use. This is a
+    /// tradeoff between the size of the parse meta and the speed of lookups. The
+    /// main reason to increase the depth is during generation there may be an
+    /// unresolvable collision at a certain depth, so we need to increase the
+    /// depth to resolve it.
+    /// @return parseMeta The parse meta built from the authoring meta and build
+    /// depth.
     function buildParseMetaV2(AuthoringMetaV2[] memory authoringMeta, uint8 maxDepth)
         internal
         pure
@@ -178,6 +229,15 @@ library LibGenParseMeta {
         }
     }
 
+    /// @dev Builds a constant string containing the parse meta, which can be
+    /// used in generated code. The string also includes a comment describing the
+    /// structure of the parse meta for future reference.
+    /// @param vm The Vm instance to use for generating the constant string.
+    /// @param authoringMetaBytes The abi-encoded authoring meta to build the
+    /// parse meta from.
+    /// @param buildDepth The build depth to use for the parse meta.
+    /// @return A constant string containing the parse meta, with a comment
+    /// describing its structure.
     function parseMetaConstantString(Vm vm, bytes memory authoringMetaBytes, uint8 buildDepth)
         internal
         pure
diff --git a/src/lib/deprecated/caller/LibDeployerDiscoverable.sol b/src/lib/deprecated/caller/LibDeployerDiscoverable.sol
deleted file mode 100644
index f5c223c..0000000
--- a/src/lib/deprecated/caller/LibDeployerDiscoverable.sol
+++ /dev/null
@@ -1,26 +0,0 @@
-// SPDX-License-Identifier: LicenseRef-DCL-1.0
-// SPDX-FileCopyrightText: Copyright (c) 2020 Rain Open Source Software Ltd
-pragma solidity ^0.8.25;
-
-import {IExpressionDeployerV4} from "../../../interface/deprecated/IExpressionDeployerV4.sol";
-import {IInterpreterStoreV2} from "../../../interface/IInterpreterStoreV2.sol";
-import {IInterpreterV2} from "../../../interface/deprecated/IInterpreterV2.sol";
-
-library LibDeployerDiscoverable {
-    /// Hack so that some deployer will emit an event with the sender as the
-    /// caller of `touchDeployer`. This MAY be needed by indexers such as
-    /// subgraph that can only index events from the first moment they are aware
-    /// of some contract. The deployer MUST be registered in ERC1820 registry
-    /// before it is touched, THEN the caller meta MUST be emitted after the
-    /// deployer is touched. This allows indexers such as subgraph to index the
-    /// deployer, then see the caller, then see the caller's meta emitted in the
-    /// same transaction.
-    /// This is NOT required if ANY other expression is deployed in the same
-    /// transaction as the caller meta, there only needs to be one expression on
-    /// ANY deployer known to ERC1820.
-    function touchDeployerV4(address deployer) internal {
-        (IInterpreterV2 interpreter, IInterpreterStoreV2 store, address expression, bytes memory io) =
-            IExpressionDeployerV4(deployer).deployExpression2("", new uint256[](0));
-        (interpreter, store, expression, io);
-    }
-}
diff --git a/src/lib/deprecated/caller/LibEncodedDispatch.sol b/src/lib/deprecated/caller/LibEncodedDispatch.sol
deleted file mode 100644
index 3589cc7..0000000
--- a/src/lib/deprecated/caller/LibEncodedDispatch.sol
+++ /dev/null
@@ -1,44 +0,0 @@
-// SPDX-License-Identifier: LicenseRef-DCL-1.0
-// SPDX-FileCopyrightText: Copyright (c) 2020 Rain Open Source Software Ltd
-pragma solidity ^0.8.25;
-
-import {SourceIndexV2, EncodedDispatch} from "../../../interface/deprecated/IInterpreterV2.sol";
-
-/// @title LibEncodedDispatch
-/// @notice Establishes and implements a convention for encoding an interpreter
-/// dispatch. Handles encoding of several things required for efficient dispatch.
-library LibEncodedDispatch {
-    /// Builds an `EncodedDispatch` from its constituent parts.
-    /// @param expression The onchain address of the expression to run.
-    /// @param sourceIndex The index of the source to run within the expression
-    /// as an entrypoint.
-    /// @param maxOutputs The maximum outputs the caller can meaningfully use.
-    /// If the interpreter returns a larger stack than this it is merely wasting
-    /// gas across the external call boundary.
-    /// @return The encoded dispatch.
-    function encode2(address expression, SourceIndexV2 sourceIndex, uint256 maxOutputs)
-        internal
-        pure
-        returns (EncodedDispatch)
-    {
-        // Both source index and max outputs are expected to be compile time
-        // constants, or at least significantly less than type(uint16).max.
-        // Generally a real world implementation would hit gas limits long before
-        // either of these values overflowed. Rather than add the gas of
-        // conditionals and errors to check for overflow, we simply truncate the
-        // values to uint16.
-        return EncodedDispatch.wrap(
-            (uint256(uint160(expression)) << 0x20) | (uint256(uint16(SourceIndexV2.unwrap(sourceIndex))) << 0x10)
-                // forge-lint: disable-next-line(unsafe-typecast)
-                | uint256(uint16(maxOutputs))
-        );
-    }
-
-    function decode2(EncodedDispatch dispatch) internal pure returns (address, SourceIndexV2, uint256) {
-        return (
-            address(uint160(EncodedDispatch.unwrap(dispatch) >> 0x20)),
-            SourceIndexV2.wrap(uint256(uint16(EncodedDispatch.unwrap(dispatch) >> 0x10))),
-            uint256(uint16(EncodedDispatch.unwrap(dispatch)))
-        );
-    }
-}
diff --git a/src/lib/ns/LibNamespace.sol b/src/lib/ns/LibNamespace.sol
index df662e7..3d139ff 100644
--- a/src/lib/ns/LibNamespace.sol
+++ b/src/lib/ns/LibNamespace.sol
@@ -2,8 +2,12 @@
 // SPDX-FileCopyrightText: Copyright (c) 2020 Rain Open Source Software Ltd
 pragma solidity ^0.8.25;
 
-import {StateNamespace, FullyQualifiedNamespace} from "../../interface/IInterpreterV3.sol";
+import {StateNamespace, FullyQualifiedNamespace} from "../../interface/IInterpreterV4.sol";
 
+/// @title LibNamespace
+/// @notice Conventions for working with namespaces as a calling contract. All of
+/// this functionality is OPTIONAL but probably useful for the majority of
+/// contracts as it enables safe (scoped) mutations in Rainlang.
 library LibNamespace {
     /// Standard way to elevate a caller-provided state namespace to a universal
     /// namespace that is disjoint from all other caller-provided namespaces.
diff --git a/src/lib/parse/LibParseMeta.sol b/src/lib/parse/LibParseMeta.sol
index 5d08143..8d03894 100644
--- a/src/lib/parse/LibParseMeta.sol
+++ b/src/lib/parse/LibParseMeta.sol
@@ -25,7 +25,23 @@ uint256 constant FINGERPRINT_MASK = 0xFFFFFF;
 /// @dev 33 = 32 bytes for expansion + 1 byte for seed
 uint256 constant META_EXPANSION_SIZE = 0x21;
 
+/// @title LibParseMeta
+/// @notice Common logic for working with parse meta, which is the data structure
+/// used to store information about the words in a parser. The parse meta is
+/// designed to be compact and efficient to lookup.
 library LibParseMeta {
+    /// @dev Given a word and a seed, return the bitmap and fingerprint for the
+    /// word. The bitmap is a uint256 with a single bit set, which can be used
+    /// to check if the word is present in an expansion. The fingerprint is a
+    /// uint256 with the low 3 bytes set, which can be used to check for
+    /// collisions when a word is found in an expansion.
+    /// @param seed The seed to use for the bitmap, which should be a byte value
+    /// between 0 and 255.
+    /// @param word The word to generate the bitmap and fingerprint for.
+    /// @return bitmap A uint256 with a single bit set, which can be used to
+    /// check if the word is present in an expansion.
+    /// @return hashed A uint256 with the low 3 bytes set, which can be used to
+    /// check for collisions when a word is found in an expansion.
     function wordBitmapped(uint256 seed, bytes32 word) internal pure returns (uint256 bitmap, uint256 hashed) {
         assembly ("memory-safe") {
             mstore(0, word)
diff --git a/test/src/lib/caller/LibContextSlow.sol b/test/src/lib/caller/LibContextSlow.sol
index 2db9524..a60e546 100644
--- a/test/src/lib/caller/LibContextSlow.sol
+++ b/test/src/lib/caller/LibContextSlow.sol
@@ -6,7 +6,7 @@ import {LibHashNoAlloc, HASH_NIL} from "rain.lib.hash/LibHashNoAlloc.sol";
 import {LibCast} from "rain.lib.typecast/LibCast.sol";
 import {LibUint256Array} from "rain.solmem/lib/LibUint256Array.sol";
 
-import {SignedContextV1} from "src/interface/IInterpreterCallerV3.sol";
+import {SignedContextV1} from "src/interface/IInterpreterCallerV4.sol";
 
 library LibContextSlow {
     using LibUint256Array for uint256;
diff --git a/test/src/lib/caller/LibDeployerDiscoverable.t.sol b/test/src/lib/caller/LibDeployerDiscoverable.t.sol
deleted file mode 100644
index d4317a6..0000000
--- a/test/src/lib/caller/LibDeployerDiscoverable.t.sol
+++ /dev/null
@@ -1,29 +0,0 @@
-// SPDX-License-Identifier: LicenseRef-DCL-1.0
-// SPDX-FileCopyrightText: Copyright (c) 2020 Rain Open Source Software Ltd
-pragma solidity =0.8.25;
-
-import {Test} from "forge-std/Test.sol";
-import {IExpressionDeployerV4} from "src/interface/deprecated/IExpressionDeployerV4.sol";
-import {LibDeployerDiscoverable} from "src/lib/deprecated/caller/LibDeployerDiscoverable.sol";
-import {IInterpreterV2} from "src/interface/deprecated/IInterpreterV2.sol";
-import {IInterpreterStoreV2} from "src/interface/IInterpreterStoreV2.sol";
-
-contract TestDeployerV4 is IExpressionDeployerV4 {
-    function deployExpression2(bytes memory, uint256[] memory)
-        external
-        returns (IInterpreterV2, IInterpreterStoreV2, address, bytes memory)
-    {}
-}
-
-contract LibDeployerDiscoverableTest is Test {
-    /// MUST be possible to touch a deployer with 0 data to support discovery.
-    function testTouchDeployerV4Mock() external {
-        TestDeployerV4 deployer = new TestDeployerV4();
-        vm.expectCall(
-            address(deployer),
-            abi.encodeWithSelector(IExpressionDeployerV4.deployExpression2.selector, "", new uint256[](0)),
-            1
-        );
-        LibDeployerDiscoverable.touchDeployerV4(address(deployer));
-    }
-}
diff --git a/test/src/lib/caller/LibEvaluable.t.sol b/test/src/lib/caller/LibEvaluable.t.sol
index 9561f62..19415c3 100644
--- a/test/src/lib/caller/LibEvaluable.t.sol
+++ b/test/src/lib/caller/LibEvaluable.t.sol
@@ -3,134 +3,64 @@
 pragma solidity =0.8.25;
 
 import {Test} from "forge-std/Test.sol";
-import {EvaluableV2} from "src/interface/deprecated/IInterpreterCallerV2.sol";
 import {LibEvaluable} from "src/lib/caller/LibEvaluable.sol";
 import {LibEvaluableSlow} from "./LibEvaluableSlow.sol";
-import {IInterpreterStoreV2} from "src/interface/IInterpreterStoreV2.sol";
-import {IInterpreterV2} from "src/interface/deprecated/IInterpreterV2.sol";
+import {IInterpreterStoreV3} from "src/interface/IInterpreterStoreV3.sol";
 
-import {EvaluableV3} from "src/interface/IInterpreterCallerV3.sol";
-import {IInterpreterV3} from "src/interface/IInterpreterV3.sol";
+import {EvaluableV4} from "src/interface/IInterpreterCallerV4.sol";
+import {IInterpreterV4} from "src/interface/IInterpreterV4.sol";
 
 contract LibEvaluableTest is Test {
-    using LibEvaluable for EvaluableV2;
-    using LibEvaluable for EvaluableV3;
+    using LibEvaluable for EvaluableV4;
 
     /// Test a known hash so that if the hash function changes, we know.
-    function testEvaluableV2KnownHash() external pure {
-        EvaluableV2 memory evaluable =
-            EvaluableV2(IInterpreterV2(address(1)), IInterpreterStoreV2(address(2)), address(3));
-        assertEq(evaluable.hash(), bytes32(0x6e0c627900b24bd432fe7b1f713f1b0744091a646a9fe4a65a18dfed21f2949c));
-    }
-
-    function testEvaluableV2HashDifferent(EvaluableV2 memory a, EvaluableV2 memory b) public pure {
-        vm.assume(a.interpreter != b.interpreter || a.store != b.store || a.expression != b.expression);
-        assertTrue(a.hash() != b.hash());
-    }
-
-    function testEvaluableV2HashSame(EvaluableV2 memory a) public pure {
-        EvaluableV2 memory b = EvaluableV2(a.interpreter, a.store, a.expression);
-        assertEq(a.hash(), b.hash());
-    }
-
-    function testEvaluableV2HashSensitivity(EvaluableV2 memory a, EvaluableV2 memory b) public pure {
-        vm.assume(a.interpreter != b.interpreter && a.store != b.store && a.expression != b.expression);
-
-        EvaluableV2 memory c;
-
-        assertTrue(a.hash() != b.hash());
-
-        // Check interpreter changes hash.
-        c = EvaluableV2(b.interpreter, a.store, a.expression);
-        assertTrue(a.hash() != c.hash());
-
-        // Check store changes hash.
-        c = EvaluableV2(a.interpreter, b.store, a.expression);
-        assertTrue(a.hash() != c.hash());
-
-        // Check expression changes hash.
-        c = EvaluableV2(a.interpreter, a.store, b.expression);
-        assertTrue(a.hash() != c.hash());
-
-        // Check match.
-        c = EvaluableV2(a.interpreter, a.store, a.expression);
-        assertEq(a.hash(), c.hash());
-
-        // Check hash doesn't include extraneous data
-        uint256 v0 = type(uint256).max;
-        uint256 v1 = 0;
-        EvaluableV2 memory d = EvaluableV2(IInterpreterV2(address(0)), IInterpreterStoreV2(address(0)), address(0));
-        assembly ("memory-safe") {
-            mstore(mload(0x40), v0)
-        }
-        bytes32 hash0 = d.hash();
-        assembly ("memory-safe") {
-            mstore(mload(0x40), v1)
-        }
-        bytes32 hash1 = d.hash();
-        assertEq(hash0, hash1);
-    }
-
-    function testEvaluableV2HashGas0() public pure {
-        EvaluableV2(IInterpreterV2(address(0)), IInterpreterStoreV2(address(0)), address(0)).hash();
-    }
-
-    function testEvaluableV2HashGasSlow0() public pure {
-        LibEvaluableSlow.hashSlow(EvaluableV2(IInterpreterV2(address(0)), IInterpreterStoreV2(address(0)), address(0)));
-    }
-
-    function testEvaluableV2ReferenceImplementation(EvaluableV2 memory evaluable) public pure {
-        assertEq(LibEvaluable.hash(evaluable), LibEvaluableSlow.hashSlow(evaluable));
-    }
-
-    /// Test a known hash so that if the hash function changes, we know.
-    function testEvaluableV3KnownHash() external pure {
-        EvaluableV3 memory evaluable =
-            EvaluableV3(IInterpreterV3(address(1)), IInterpreterStoreV2(address(2)), hex"030405");
+    function testEvaluableV4KnownHash() external pure {
+        EvaluableV4 memory evaluable =
+            EvaluableV4(IInterpreterV4(address(1)), IInterpreterStoreV3(address(2)), hex"030405");
         assertEq(evaluable.hash(), bytes32(0x389371bb1206fa55c5ce170f501ebbe5aacd211e163a6076a349c8bc6437aaa9));
     }
 
-    function testEvaluableV3HashDifferent(EvaluableV3 memory a, EvaluableV3 memory b) public pure {
+    function testEvaluableV4HashDifferent(EvaluableV4 memory a, EvaluableV4 memory b) public pure {
         vm.assume(
             a.interpreter != b.interpreter || a.store != b.store || keccak256(a.bytecode) != keccak256(b.bytecode)
         );
         assertTrue(a.hash() != b.hash());
     }
 
-    function testEvaluableV3HashSame(EvaluableV3 memory a) public pure {
-        EvaluableV3 memory b = EvaluableV3(a.interpreter, a.store, a.bytecode);
+    function testEvaluableV4HashSame(EvaluableV4 memory a) public pure {
+        EvaluableV4 memory b = EvaluableV4(a.interpreter, a.store, a.bytecode);
         assertEq(a.hash(), b.hash());
     }
 
-    function testEvaluableV3HashSensitivity(EvaluableV3 memory a, EvaluableV3 memory b) public pure {
+    function testEvaluableV4HashSensitivity(EvaluableV4 memory a, EvaluableV4 memory b) public pure {
         vm.assume(
             a.interpreter != b.interpreter && a.store != b.store && keccak256(a.bytecode) != keccak256(b.bytecode)
         );
 
-        EvaluableV3 memory c;
+        EvaluableV4 memory c;
 
         assertTrue(a.hash() != b.hash());
 
         // Check interpreter changes hash.
-        c = EvaluableV3(b.interpreter, a.store, a.bytecode);
+        c = EvaluableV4(b.interpreter, a.store, a.bytecode);
         assertTrue(a.hash() != c.hash());
 
         // Check store changes hash.
-        c = EvaluableV3(a.interpreter, b.store, a.bytecode);
+        c = EvaluableV4(a.interpreter, b.store, a.bytecode);
         assertTrue(a.hash() != c.hash());
 
         // Check bytecode changes hash.
-        c = EvaluableV3(a.interpreter, a.store, b.bytecode);
+        c = EvaluableV4(a.interpreter, a.store, b.bytecode);
         assertTrue(a.hash() != c.hash());
 
         // Check match.
-        c = EvaluableV3(a.interpreter, a.store, a.bytecode);
+        c = EvaluableV4(a.interpreter, a.store, a.bytecode);
         assertEq(a.hash(), c.hash());
 
         // Check hash doesn't include extraneous data
         uint256 v0 = type(uint256).max;
         uint256 v1 = 0;
-        EvaluableV3 memory d = EvaluableV3(IInterpreterV3(address(0)), IInterpreterStoreV2(address(0)), hex"");
+        EvaluableV4 memory d = EvaluableV4(IInterpreterV4(address(0)), IInterpreterStoreV3(address(0)), hex"");
         assembly ("memory-safe") {
             mstore(mload(0x40), v0)
         }
@@ -142,24 +72,24 @@ contract LibEvaluableTest is Test {
         assertEq(hash0, hash1);
     }
 
-    function testEvaluableV3HashGas0() public pure {
-        EvaluableV3(IInterpreterV3(address(0)), IInterpreterStoreV2(address(0)), hex"").hash();
+    function testEvaluableV4HashGas0() public pure {
+        EvaluableV4(IInterpreterV4(address(0)), IInterpreterStoreV3(address(0)), hex"").hash();
     }
 
-    function testEvaluableV3BytecodeLengthSensitivity() public pure {
-        EvaluableV3 memory a = EvaluableV3(IInterpreterV3(address(0)), IInterpreterStoreV2(address(0)), hex"01");
+    function testEvaluableV4BytecodeLengthSensitivity() public pure {
+        EvaluableV4 memory a = EvaluableV4(IInterpreterV4(address(0)), IInterpreterStoreV3(address(0)), hex"01");
         // `b` is identical to `a` except for the bytecode length.
         // Note the trailing `00` in the bytecode would be the same in memory as
         // the `00` padding that the allocator would add to `a`'s bytecode.
-        EvaluableV3 memory b = EvaluableV3(IInterpreterV3(address(0)), IInterpreterStoreV2(address(0)), hex"0100");
+        EvaluableV4 memory b = EvaluableV4(IInterpreterV4(address(0)), IInterpreterStoreV3(address(0)), hex"0100");
         assertTrue(a.hash() != b.hash());
     }
 
-    function testEvaluableV3HashGasSlow0() public pure {
-        LibEvaluableSlow.hashSlow(EvaluableV3(IInterpreterV3(address(0)), IInterpreterStoreV2(address(0)), hex""));
+    function testEvaluableV4HashGasSlow0() public pure {
+        LibEvaluableSlow.hashSlow(EvaluableV4(IInterpreterV4(address(0)), IInterpreterStoreV3(address(0)), hex""));
     }
 
-    function testEvaluableV3ReferenceImplementation(EvaluableV3 memory evaluable) public pure {
+    function testEvaluableV4ReferenceImplementation(EvaluableV4 memory evaluable) public pure {
         assertEq(LibEvaluable.hash(evaluable), LibEvaluableSlow.hashSlow(evaluable));
     }
 }
diff --git a/test/src/lib/caller/LibEvaluableSlow.sol b/test/src/lib/caller/LibEvaluableSlow.sol
index 1a44490..ff13b0e 100644
--- a/test/src/lib/caller/LibEvaluableSlow.sol
+++ b/test/src/lib/caller/LibEvaluableSlow.sol
@@ -2,8 +2,8 @@
 // SPDX-FileCopyrightText: Copyright (c) 2020 Rain Open Source Software Ltd
 pragma solidity =0.8.25;
 
-import {EvaluableV2} from "src/interface/deprecated/IInterpreterCallerV2.sol";
-import {EvaluableV3} from "src/interface/IInterpreterCallerV3.sol";
+import {EvaluableV2} from "src/interface/deprecated/v1/IInterpreterCallerV2.sol";
+import {EvaluableV4} from "src/interface/IInterpreterCallerV4.sol";
 
 library LibEvaluableSlow {
     function hashSlow(EvaluableV2 memory evaluable) internal pure returns (bytes32) {
@@ -16,7 +16,7 @@ library LibEvaluableSlow {
         );
     }
 
-    function hashSlow(EvaluableV3 memory evaluable) internal pure returns (bytes32) {
+    function hashSlow(EvaluableV4 memory evaluable) internal pure returns (bytes32) {
         return keccak256(
             abi.encodePacked(
                 keccak256(
diff --git a/test/src/lib/deprecated/caller/LibEncodedDispatch.t.sol b/test/src/lib/deprecated/caller/LibEncodedDispatch.t.sol
deleted file mode 100644
index 6c6422f..0000000
--- a/test/src/lib/deprecated/caller/LibEncodedDispatch.t.sol
+++ /dev/null
@@ -1,18 +0,0 @@
-// SPDX-License-Identifier: LicenseRef-DCL-1.0
-// SPDX-FileCopyrightText: Copyright (c) 2020 Rain Open Source Software Ltd
-pragma solidity =0.8.25;
-
-import {Test} from "forge-std/Test.sol";
-import {LibEncodedDispatch} from "src/lib/deprecated/caller/LibEncodedDispatch.sol";
-import {SourceIndexV2} from "src/interface/IInterpreterV3.sol";
-
-contract LibEncodedDispatchTest is Test {
-    function testRoundTrip(address expression, SourceIndexV2 sourceIndex, uint16 maxOutputs) public pure {
-        sourceIndex = SourceIndexV2.wrap(bound(SourceIndexV2.unwrap(sourceIndex), 0, type(uint16).max));
-        (address expressionDecoded, SourceIndexV2 sourceIndexDecoded, uint256 maxOutputsDecoded) =
-            LibEncodedDispatch.decode2(LibEncodedDispatch.encode2(expression, sourceIndex, maxOutputs));
-        assertEq(expression, expressionDecoded);
-        assertEq(SourceIndexV2.unwrap(sourceIndex), SourceIndexV2.unwrap(sourceIndexDecoded));
-        assertEq(maxOutputs, maxOutputsDecoded);
-    }
-}
diff --git a/test/src/lib/ns/LibNamespaceSlow.sol b/test/src/lib/ns/LibNamespaceSlow.sol
index 1333807..8323e83 100644
--- a/test/src/lib/ns/LibNamespaceSlow.sol
+++ b/test/src/lib/ns/LibNamespaceSlow.sol
@@ -2,7 +2,7 @@
 // SPDX-FileCopyrightText: Copyright (c) 2020 Rain Open Source Software Ltd
 pragma solidity =0.8.25;
 
-import {StateNamespace, FullyQualifiedNamespace} from "src/interface/IInterpreterV3.sol";
+import {StateNamespace, FullyQualifiedNamespace} from "src/interface/IInterpreterV4.sol";
 
 library LibNamespaceSlow {
     /// Implements an abi encoding based version of `qualifyNamespace` that is