One of the social benefits of open source packages is that anyone can download them and start learning -- not just about that platform -- but about content management systems in general. In our experience, this is particularly valuable for developers. For example, you can easily download Typo3, a popular PHP-based system, and run it on your laptop or local network (the installer will unpack Apache and MySQL if you don't already have). By playing around with the tool, you can learn a lot of CMS concepts, such as templating, user management, applying pre-set functions and components, embedding custom code snippets, and so on. Check out this sysadmin interface. For end-users, the story is a bit different. Editing content snippets in Typo3 seems easy enough. But an important bellweather for usability is how simply can a novice user create a new page. And here, Typo3 -- like most open-source CMS packages -- comes up a bit short out of the tarball. See, for example this screen. Of course, since usability is highly situational, your mileage will vary, but just remember that what's simple for the developer may remain complicated for the author. Our larger point, though: all software comes with its own benefits and quirks, but with open-source (and increasingly some commercial) tools, you can try before you commit -- and learn something along the way regardless...