Why would I suggest ScrewTurn as worth a turn or two? Well:

• It depends on whether you are looking for a Windows based stack or a Linux based stack. There are lots of options out there for Linux based stacks – but for Windows there are far fewer.
• As mentioned above its free, open source, and licensed under the well-known, widely utilized GPLv2.
• ScrewTurn also seems to be under continuous development with regular releases and well supported forums…and its not some new project that just popped out of the woodwork – its been around for a while.
• Its extremely easy to setup. Anyone who can learn how to purchase some shared hosting and use an FTP client can get ScrewTurn up and running within minutes.
• It supports a good variety of databases (e.g. MSSQL and MySQL) but also allows for flat filesystem site creation (what I use on freewargamer). This makes setup/management even simpler and reduces the requirements in a shared host (which usually limit or don’t provide database access).
• The UI is simple and easy to use. Its intuitive.
• It has WYSIWYG editing of articles.
• It supports Active Directory integration!

The list could go on – but check it out for yourself. Enjoy! (P.S. they recently released the final version of 3.0 which is pretty awesome).