Actually, you should ask phppp about the 2.2.5 status. He's the developer who took on the task of releasing the update release for XOOPS 2.2.4. ANd xuser, since you're chinese just like phppp, you have easy access to that information.
Bytheway, the XOOPS project on sf.net ranks pretty high, so it probably isn't dead. But you're right, we haven't seen many updates in the svn recently.
But we knew this would happen:
1. when 2.0.16 was released, it was announced as the last 2.0.x release. Also, it was announced that development would focus on the next generation XOOPS code.
2. There have been 2 alpha releases for the 2.3 code branch. The community response to those releases was absolutely minimal. Judging by that, you could say that the XOOPS project was dead. It showed however, that the 'develop in public, try to involve as many people as possible, give everyone a chance to show their (hidden) talents' approach wasn't working. So, the developers now work privately and release whenever they feel it is right. The benefit of this could be that they release stuff that others can work with and build on, not just read along.
3. If, by pure chance and sheer luck, you're a talented developer and want to pool your talents with the rest of the core developers, please do contact phppp, skalpa and/or rowd about this.
So: the status of 2.2.x is in short: not recommended for new users, maitenance releases only, RC release published, but very little actual feedback on the RC.
Ask phppp to make it final, as the very last of the 2.2 series of XOOPS releases. If that makes you feel better
Herko