If you’re looking for an application stack to run on *any* OS, particularly one of the very famous and useful open source applications (subversion, wordpress, joomla, drupal, apache, ruby, moodle, mysql, php, trac, …) and want to get started quickly, i would suggest bitnami for most your needs.
And especially if you’re stuck with a Windows server :p but really need to set something useful (server application) up and running, chances are, bitnami will have a stack you can download, click and install. They even have got Ruby on Rails. And the growth in the last few weeks has been quite considerable (ito offerings) so there’s very little excuse for not trying out (self-hosting) any of these wicked-cool apps on your internal networks 😉