I have been thinking about how to deal with releases of phpGroupWare. For me it is a technical, procedural and political question.
Over the last few months I have been playing with Drupal a fair bit. I love Drupal. It is simple to install, skin and hack. The community is great. The website is massive and has almost anything you want about Drupal. They dog food their stuff. I have quite a few clients using Drupal for their sites, they love it.