Free Software Sources
. No matter what you want to do, you can probably find a free program that will do it at SourceForge.
. Quality of the programs varies widely, but if you pay attention to last revision dates (be wary if it hasn't been updated in a few years or hasn't been updated since it was posted) and the number of downloads (more is usually better), you can skip over the lesser stuff.
. Not sure how they handle malware prevention, but I've never been infected by any of the plethora of stuff I've downloaded.
. Here's the sources others have contributed, in a handy list with links.
MS Visual BASIC (Brennn10)
Softpedia (LinuxH4x0r, ll.13)
Download.com (CNET/ZDNET) (Goodhart, ll.13)
The Pirate Bay (ll.13)