Links and reviews to programs that I have found useful.
Open Source Workstation:

• Gimp: Gnu Image Maniplulation Package. (Linux, Windows, other)
• Inkscape: Vector drawing program. Similiar to Corel Draw, Adobe Illustrator, etc... (Linux, Windows, Mac, Other)
• Open Office v2.x: Office suite very useful and stable. It includes word processing, spreadsheet, database, presentation and drawing. (Linux, Windows, Mac, other)
• Wink: Flash tutorial creation program. Make flash demonstrations of what you are doing.
• Dev-c++: C++ development environment.
• Glade: GTK user interface design program.
• Firefox: Internet web browser
• Thunderbird: Email Client

Open Source Web Applications:

• Moodle: A great teaching tool.

Freeware:

• ExplorerXP: a replacement for Windows Explorer. I don't always use it but it has a nice feature of being able to tell you how much space a given set of directories use. (Free for non-commercial use) (Windows)