The OSSwin Project :Open Source Software for Windows

The OSSwin Project, Open Source for Windows, provides a huge range of open source software for every conceivable purpose:
http://osswin.sourceforge.net/

Here's a list of categories of what is available:

• audio editing tools
• business software
• CAD software and Electronic Design Automation (EDA)
• CD writing
• compression/zip
• Databases
• desktop environments & windows shell replacements
• dictionaries
• drivers/hardware
• educational
• emulators
• encyclopedia
• filesharing
• FTP clients
• firewall and NAT
• file systems
• graphics
• instant messaging
• internet voice chat
• IRC clients
• mail & news
• media players (audio & video & codecs)
• networking tools
• NTP clients
• office tools
• operating systems
• postscript viewers
• programming
• remote access
• Science & Maths (including mathematics, biology, geographic information systems)
• security, privacy and protection
• server software
• SCP clients
• stream downloaders
• text editors
• utilities
• video capture/processing
• VJ software
• webbrowsers
• webgrabbers and download managers
• X-servers
  

Click the link below to access the software:
http://osswin.sourceforge.net/

For more information on Open Source visit the Open Source Initiative.