Forum OpenACS Q&A: use cvs tag oacs-4-6-1-b2
If you want stability, you need to use a specific release, like 4.6, 4.6.1, 4.6.1 beta1, 4.6.2, etc. The "oacs-4-6" cvs tag is not a specific release. The cvs tags "oacs-4-6-final", "oacs-4-6-1-b1", and "oacs-4-6-1-b2" are.
Of course, it's quite true that there might be a very bad bug in, say, "oacs-4-6-1-b2", which someone has fixed on the "oacs-4-6" branch but not yet tagged for release. And in that case, the tip of the branch will in one sense, coincidentally, be more "stable" than the last tagged release - it will work better. But that's an accident, and far from guaranteed. By design and common sense, any released version should be more "stable" than source code that's a moving target. And the tip of any branch, be it the head or the 4.6 branch, is always a moving target. The only difference between head and oacs-4-6, is that oacs-4-6 is probably a much slower moving target than the head.