ParadoX Inc

I’ve recently found a nice webmail project that so far is great and has lots of potential to be better, RoundCube. It’s a browser-based IMAP client written in PHP using a MySQL database for user preferences and settings. The interface is very slick and works great in most browsers (IE6 has some issues due to the lack of PNG transparency support) as you can tell from the screen shots.
The community is fairly active and very helpful, they are constantly working on bug fixes and implementing new features. Plus being PHP it’s easy to add your own features, just post your additions in the Third-Party section in the forums and someone will appreciate it! The SVN has a lot of these new features and is where you’d go to get the latest code base, if messing around with subversion isn’t your bag of beans there are snapshots posted which are as easy to install as the releases.