diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6bf23aa4..e2148266 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,6 +1,6 @@
 # Copyright 2020-2021 Peter Dimov
 # Copyright 2021 Andrey Semashev
-# Copyright 2021-2025 Alexander Grund
+# Copyright 2021 Alexander Grund
 # Copyright 2022 James E. King III
 #
 # Distributed under the Boost Software License, Version 1.0.
@@ -18,25 +18,198 @@ on:
       - bugfix/**
       - feature/**
       - fix/**
-      - github/**
       - pr/**
-    paths-ignore:
-      - LICENSE
-      - meta/**
-      - README.md
 
 concurrency:
   group: ${{format('{0}:{1}', github.repository, github.ref)}}
   cancel-in-progress: true
 
+env:
+  GIT_FETCH_JOBS: 8
+  NET_RETRY_COUNT: 5
+  B2_CI_VERSION: 1
+  B2_VARIANT: debug,release
+  B2_LINK: shared,static
+  LCOV_BRANCH_COVERAGE: 0
+  CODECOV_NAME: Github Actions
+
 jobs:
-  call-boost-ci:
-    name: Run Boost.CI
-    uses: boostorg/boost-ci/.github/workflows/reusable.yml@master
-    with:
-      branch_coverage: false
-    secrets:
-      CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
-      COVERITY_SCAN_NOTIFICATION_EMAIL: ${{ secrets.COVERITY_SCAN_NOTIFICATION_EMAIL }}
-      COVERITY_SCAN_TOKEN: ${{ secrets.COVERITY_SCAN_TOKEN }}
+  posix:
+    defaults:
+      run:
+        shell: bash
+
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          # Linux, gcc
+          - { name: Collect coverage, coverage: yes,
+              compiler: gcc-8,     cxxstd: '11,14,17,2a',    os: ubuntu-20.04, install: 'g++-8-multilib', address-model: '32,64' }
+          - { name: Collect coverage, coverage: yes,
+              compiler: gcc-13,    cxxstd: '11,14,17,2a',    os: ubuntu-24.04, install: 'g++-13-multilib', address-model: '32,64' }
+
+    timeout-minutes: 120
+    runs-on: ${{matrix.os}}
+    container:
+      image: ${{matrix.container}}
+      volumes:
+        - /node20217:/node20217:rw,rshared
+        - ${{ startsWith(matrix.container, 'ubuntu:1') && '/node20217:/__e/node20:ro,rshared' || ' ' }}
+    env: {B2_USE_CCACHE: 1}
+
+    steps:
+      - name: Setup environment
+        run: |
+            if [ -f "/etc/debian_version" ]; then
+                echo "DEBIAN_FRONTEND=noninteractive" >> $GITHUB_ENV
+                export DEBIAN_FRONTEND=noninteractive
+            fi
+            if [ -n "${{matrix.container}}" ] && [ -f "/etc/debian_version" ]; then
+                apt-get -o Acquire::Retries=$NET_RETRY_COUNT update
+                apt-get -o Acquire::Retries=$NET_RETRY_COUNT install -y sudo software-properties-common curl
+                # Need (newer) git, and the older Ubuntu container may require requesting the key manually using port 80
+                curl -sSL --retry ${NET_RETRY_COUNT:-5} 'http://keyserver.ubuntu.com/pks/lookup?op=get&search=0xE1DD270288B4E6030699E45FA1715D88E1DF1F24' | sudo gpg --dearmor -o /etc/apt/trusted.gpg.d/git-core_ubuntu_ppa.gpg
+                for i in {1..${NET_RETRY_COUNT:-3}}; do sudo -E add-apt-repository -y ppa:git-core/ppa && break || sleep 10; done
+                apt-get -o Acquire::Retries=$NET_RETRY_COUNT update
+                osver=$(lsb_release -sr | cut -f1 -d.)
+                pkgs="g++ git"
+                # Ubuntu 22+ has only Python 3 in the repos
+                if [ -n "$osver" ] && [ "$osver" -ge "22" ]; then
+                  pkgs+=" python-is-python3 libpython3-dev"
+                else
+                  pkgs+=" python libpython-dev"
+                fi
+                apt-get -o Acquire::Retries=$NET_RETRY_COUNT install -y $pkgs
+            fi
+            # For jobs not compatible with ccache, use "ccache: no" in the matrix
+            if [[ "${{ matrix.ccache }}" == "no" ]]; then
+                echo "B2_USE_CCACHE=0" >> $GITHUB_ENV
+            fi
+            git config --global pack.threads 0
+            if [[ "${{matrix.container}}" == "ubuntu:1"* ]]; then
+              # Node 20 doesn't work with Ubuntu 16/18 glibc: https://github.com/actions/checkout/issues/1590
+              curl -sL https://unofficial-builds.nodejs.org/download/release/v20.9.0/node-v20.9.0-linux-x64-glibc-217.tar.xz | tar -xJ --strip-components 1 -C /node20217
+            fi
+            ! command -v cmake &> /dev/null || echo "B2_FLAGS=--nowide-enable-cmake" >> $GITHUB_ENV
+
+      - uses: actions/checkout@v4
+        with:
+          # For coverage builds fetch the whole history, else only 1 commit using a 'fake ternary'
+          fetch-depth: ${{ matrix.coverage && '0' || '1' }}
+
+      - name: Cache ccache
+        uses: actions/cache@v4
+        if: env.B2_USE_CCACHE
+        with:
+          path: ~/.ccache
+          key: ${{matrix.os}}-${{matrix.container}}-${{matrix.compiler}}-${{github.sha}}
+          restore-keys: |
+            ${{matrix.os}}-${{matrix.container}}-${{matrix.compiler}}-
+            ${{matrix.os}}-${{matrix.container}}-${{matrix.compiler}}
+
+      - name: Fetch Boost.CI
+        uses: actions/checkout@v4
+        with:
+          repository: boostorg/boost-ci
+          ref: master
+          path: boost-ci-cloned
+
+      - name: Get CI scripts folder
+        run: |
+            # Copy ci folder if not testing Boost.CI
+            [[ "$GITHUB_REPOSITORY" =~ "boost-ci" ]] || cp -r boost-ci-cloned/ci .
+            rm -rf boost-ci-cloned
+
+      - name: Install packages
+        if: startsWith(matrix.os, 'ubuntu')
+        run: |
+            SOURCE_KEYS=(${{join(matrix.source_keys, ' ')}})
+            SOURCES=(${{join(matrix.sources, ' ')}})
+            # Add this by default
+            SOURCES+=(ppa:ubuntu-toolchain-r/test)
+            for key in "${SOURCE_KEYS[@]}"; do
+                for i in {1..$NET_RETRY_COUNT}; do
+                    keyfilename=$(basename -s .key $key)
+                    curl -sSL --retry ${NET_RETRY_COUNT:-5} "$key" | sudo gpg --dearmor > /etc/apt/trusted.gpg.d/${keyfilename} && break || sleep 10
+                done
+            done
+            for source in "${SOURCES[@]}"; do
+                for i in {1..$NET_RETRY_COUNT}; do
+                    sudo add-apt-repository $source && break || sleep 10
+                done
+            done
+            sudo apt-get -o Acquire::Retries=$NET_RETRY_COUNT update
+            if [[ -z "${{matrix.install}}" ]]; then
+                pkgs="${{matrix.compiler}}"
+                pkgs="${pkgs/gcc-/g++-}"
+            else
+                pkgs="${{matrix.install}}"
+            fi
+            sudo apt-get -o Acquire::Retries=$NET_RETRY_COUNT install -y $pkgs
+
+      - name: Setup GCC Toolchain
+        if: matrix.gcc_toolchain
+        run: |
+            GCC_TOOLCHAIN_ROOT="$HOME/gcc-toolchain"
+            echo "GCC_TOOLCHAIN_ROOT=$GCC_TOOLCHAIN_ROOT" >> $GITHUB_ENV
+            if ! command -v dpkg-architecture; then
+                apt-get install -y dpkg-dev
+            fi
+            MULTIARCH_TRIPLET="$(dpkg-architecture -qDEB_HOST_MULTIARCH)"
+            mkdir -p "$GCC_TOOLCHAIN_ROOT"
+            ln -s /usr/include "$GCC_TOOLCHAIN_ROOT/include"
+            ln -s /usr/bin "$GCC_TOOLCHAIN_ROOT/bin"
+            mkdir -p "$GCC_TOOLCHAIN_ROOT/lib/gcc/$MULTIARCH_TRIPLET"
+            ln -s "/usr/lib/gcc/$MULTIARCH_TRIPLET/${{matrix.gcc_toolchain}}" "$GCC_TOOLCHAIN_ROOT/lib/gcc/$MULTIARCH_TRIPLET/${{matrix.gcc_toolchain}}"
+
+      - name: Setup multiarch
+        if: matrix.multiarch
+        run: |
+          sudo apt-get install --no-install-recommends -y binfmt-support qemu-user-static
+          sudo docker run --rm --privileged multiarch/qemu-user-static --reset -p yes
+          git clone https://github.com/jeking3/bdde.git
+          echo "$(pwd)/bdde/bin/linux" >> ${GITHUB_PATH}
+          echo "BDDE_DISTRO=${{ matrix.distro }}" >> ${GITHUB_ENV}
+          echo "BDDE_EDITION=${{ matrix.edition }}" >> ${GITHUB_ENV}
+          echo "BDDE_ARCH=${{ matrix.arch }}" >> ${GITHUB_ENV}
+          echo "B2_WRAPPER=bdde" >> ${GITHUB_ENV}
+
+      - name: Setup Boost
+        env:
+          B2_ADDRESS_MODEL: ${{matrix.address-model}}
+          B2_COMPILER: ${{matrix.compiler}}
+          B2_CXXSTD: ${{matrix.cxxstd}}
+          B2_SANITIZE: ${{matrix.sanitize}}
+          B2_STDLIB: ${{matrix.stdlib}}
+        run: source ci/github/install.sh
+
+      - name: Setup coverage collection
+        if: matrix.coverage
+        run: ci/github/codecov.sh "setup"
+
+      - name: Run tests
+        if: '!matrix.coverity'
+        run: ci/build.sh
+
+      - name: Run tests with simulated no LFS support
+        env:
+          B2_FLAGS: boost.nowide.lfs=no
+        run: ci/build.sh
+
+      - name: Collect coverage
+        if: matrix.coverage
+        run: ci/codecov.sh "upload"
+        env:
+          BOOST_CI_CODECOV_IO_UPLOAD: skip
+
+      - name: Upload coverage
+        if: matrix.coverage
+        uses: codecov/codecov-action@v4
+        with:
+          disable_search: true
+          file: coverage.info
+          name: Github Actions
+          token: ${{secrets.CODECOV_TOKEN}}
+          verbose: true