Linux
A means to world liberation! our goal is to provide all the information necessary to make your use of linux a success.
http://www.linux.com
Linux
Linux
http://www.linux.be
MacOS
Leopard collects hundreds of features into one os so innovative, it will completely transform your mac. a dramatic new desktop. one-click data time travel. the power to see inside files without opening them. discover the future of your mac. take a tour of the top features in mac os x leopard.
http://www.apple.com/macosx
Windows
Visit the official home page for windows products and technologies. learn how to get products, find help and support, and use windows to accomplish your favorite things.
http://www.microsoft.com/windows/default.mspx