Spring\'s 3.0 version is now GA release, before that they have launched 3.0 RC1, RC2 version Also, there was Spring 3.0
GA = General availability (a release); should be very stable and feature complete
RC = Release candidate; probably feature complete and should be pretty stable - problems should be relatively rare and minor, but worth reporting to try to get them fixed for release.
M = Milestone build - probably not feature complete; should be vaguely stable (i.e. it's more than just a nightly snapshot) but may still have problems.
SR = Service Release (subsequent maintenance releases that come after major -RELEASE
).
Refer to Software release life cycle on Wikipedia. The whole life cycle is described in detail.
I think:
Usually, its Milestone release, then RC releases and then a GA release.
In an Open Source project, you usually would have a public plan for releases, which can actually give you good ideas about the project's release plans. Like, what quality criteria determines a RC, GA or a Milestone release.