On Nov 18, 2011, at 08:29 , Chad Perrin wrote:

> * 1.9.3-p0 is the current release version.  The -p0 means "patch number
>  zero".
> 
> * 1.9.3-head is the cutting-edge version in the main development
>  repository, which may well include some incomplete feature additions or
>  changes.

I don't know if rvm distinguishes yet, but I'm going to assume it does.

1.9.3-head should be the head of the 1_9_3 branch or at least the head of the 1_9 branch. It can/will contain unreleased changes, but no feature additions.

trunk proper has cut over to 2.0 already and WILL contain feature additions and, more than likely, unstable code.