Wikipedia is an amazing resource and someone has compiled a huge list of free open source programs at List of Open Source Software Packages.
The list is broken down by type including math, finance, word processing, assisting technology, file manager, games, media, internet, networking, education, and so many more.
If a link is in red, that means that documentation in Wikipedia has not been written, so if you are familiar with the program, consider clicking on that link and filling in the blanks to help all of us. Many of the links include a link to the software site, which would also help even if there is no Wikipedia documentation. And you can add to this list, which is part of the fun of working on a wiki and contributing to the largest resource for knowledge in the world – and FREE, too.
Now, the programs listed are considered free, but if you really like them and use them, do consider donating to their cause so they can remain free and their developers can keep the roof over their head and food in their children’s mouths. ;-)
And while I’m looking at this huge, overwhelming list, besides WordPress and Firefox, what are some of your favorite open source, free programs?