This may be one of the oldest open source projects you've never heard of. Fourteen years after it kicked off as a UI layer for the Zope content management system, Plone has a community of its own. This mature CMS is a heavy-duty substitute for Moveable Type and WordPress that delivers blogging, calendaring and concise dashboards. Version 4 reportedly doubles the speed and performance of its predecessor, sports an all-new UI theme that's modern-looking and easy to customize, and includes a graphical HTML editor for easier coding. With versions for all major platforms, Plone 4.0 now includes point-and-click installers for Mac OS X and Windows, as well as a universal installer for Linux and Unix.