Reference
Changelog
How releases work, and where to find what shipped.
Quack ships two tracks: a release-candidate build cut for testing, and a stable build cut once an RC has been validated. The version you're running shows in the status bar — click it to see details.
For the full list of changes release by release, check the app's own release notes or its GitHub releases page — this reference page intentionally doesn't duplicate that list, since it changes every release and this page would immediately go stale.