The developers at Roundcube finally decided to release version 0.2 as a stable release. I’ve been using the beta versions without problems but thought it wouldn’t be prudent to let you do the same.
New things included are a simple installer function, HTML editor (TniyMCE) for creating HTML email and collapsable folders and much more. If you want to upgrade there are some instructions on how to do that in the most simple way possible without interfering too much with existing users.
By the way, because of the installer option I’ve also rewritten the installation instructions.