To get my feet wet, I wanted to test an installation of WordPress MU (multi-user) edition. The installation seems too problematic on a Windows workstation, even when running in an environment such as AppServ , WAMP, XAMPP, or Uniform Server. My preference is XAMPP. I have tested and used all these environments. I originally preferred the Uniform Server as it boasts about it's portability. It was able to do so by creating a virtual drive letter and worked great, until I installed another web application that would not work. I resorted to XAMPP and that tough little web app worked as advertised. I don't know what the difference is between the two applications, however, I don't need to. Another, server, untested at the time of this writing is AMPPS. After all the effort and trouble attempting to install WordPress MU on one of the above environments, I discovered rBuilder.
rBuilder is a virtual appliance (or a VMware virtual machine image) that is already configured with an installation of WordPress MU on a Linux installation. The WordPress MU Appliance is available in many flavors.
The installation guide is available here: http://wiki.rpath.com/wiki/Appliance:WordPressMU_Appliance