Free software for economists

Now that I have a blog (zero comments still...), I thought it'd be nice to get a Googlepage. So I did, and to get things started, I compiled a list of free and open source software for economists, with links to the relevant Web pages, and comments on each package based on my own direct experience.

Actually, this list should be useful to anybody who has to deal with math on a daily basis; this includes, well, mathematicians, statisticians, physicists, etc. However, my sense is that these folks are way ahead of us economists when it comes to using powerful, featureful free software. And there's no reason why they should be having all the fun!

The current list is not meant to be exhaustive. If you know and use a package that is not listed, please let me know by dropping a comment here. In general, constructive criticism is much appreciated. Thanks!