I’ve been playing around with Ubuntu recently and have just discovered that if you insert an Ubuntu Live CD in a Windows machine (with Autoplay enabled), a browser window opens with a selection of Windows open source software. This functionality is taken from The Open CD, and you can read more about it on the Ubuntu Wiki. This quote is from the Ubuntu website:
The Ubuntu Live CD contains a small collection of open source applications for Windows.
Inserting the Live CD while running Windows brings up a browser with some information about each application and the option to install it. The browser uses technology and content from TheOpenCD project, with a custom Ubuntu skin. There is also a brief introduction to Ubuntu with screenshots.