1.9.x, though, is going to go through a lot of iterations, so it's possible that what might be considered "stable" now won't be so stable later. A good example is that 1.9.0 (and 1.9.0p1, which fixes some of 1.9.0 by backporting 1.9.1) is relatively stable for use, however, in it's current state, 1.9.1 isn't stable, mainly because we haven't compiled it as a release and are still working on it. The SVN trunk branch is the latest of 1.9.x, and that currently means 1.9.1. When 1.9.1 is released, trunk will be 1.9.2 in progress. I hope that clears up some things. Just keep in mind that we probably will not consider 1.9.x to ever be truly stable, and when it does get to that point, we will probably reversion it to 2.0 at that point.