You should look at the "Next release" date, not at the "frozen stage" date - 3.6 is only a few (five) days overdue.
Let me allow to explain the
release plan in more detail first:
- Development happens in a shared location called a repository. Inside this repository, the most recent (and potentially unstable) version of the code is called next.
- On the 17th of December/June the repository enters the "frozen" state - no new features are accepted for a month, only bug fixes (to weed out bugs).
- On the 17th of January/July the repository enters the "open" (normal) state again; moreover, the team creates "release branches" (essentially, copies of the code/data). At this point, the team has two parallel locations to work on:
- next (for new features/breaking changes), and
- the release branch for the new FlightGear version (to clean up the code, fix bugs, etc.)
Note that, even though there is a release branch now, the new FlightGear version has not come out - this allows interested people to try it out and report bugs before the new version is released officially. - The actual release happens only around the 17th of February/August (unless critical bugs are discovered at the last minute); moreover, it takes some days to package and distribute the files (due to their size and the fact that the core development team is small - a hitch could easily delay the process a bit). This time, the only potentially critical issue I've seen is a change in the Mac build which makes FG crash on launch (a Mac developer is working on it).
That said, if you're on Windows, you can test the
latest 3.6 "nightly" build - it's what will be released if no further fixes are needed.