Introducing Eta v4

[bgub]

Cross-posted from https://www.bengubler.com/posts/2025-09-17-introducing-eta-v4

I released Eta for the first time five years ago! Since then, it's grown to be depended on by hundreds of packages and downloaded 1M+ times per week.

I consider Eta to be mostly "a completed work" since v3, which was released in June 2023. But I wasn't satisfied with the bundling, testing, linting, and CI/CD aspects of the project so I rewrote it! (Then extracted my changes, after the fact, into a new TS library template called ts-base).

There are a few more changes to be aware of:

• Eta is now ESM-only by default. It's 2025 and this is the right choice!
• I transferred the repository (and other associated repositories) to my personal GitHub account, bgub. Since I'm the primary contributor, I think this will simplify maintenance and reduce confusion.
• Eta will continue to be published on https://deno.land/x/, but I recommend that users use https://jsr.io/@bgub/eta instead.
• To use the browser-compatible version of Eta, you must import from eta/core, since we're now using much cleaner "exports" in our package.json.