I'm not a great programmer myself (my main job is more electrical engineering) and have never really helped out with any open source projects, but I've benefited greatly from free and/or open-source software (MySQL, OpenOffice, Firefox, Apache, PHP, Java, etc.) and at some point would like to make some modest financial contributions to help keep this stuff going.

I'm wondering, what are the best non-profits to make financial contributions?

I'm aware of:

• Open Source Initiative (founded 10 years ago by several prominent figures including programmer and "The Cathedral and the Bazaar" author Eric S. Raymond)
• Free Software Foundation
• Mozilla Foundation
• Apache Foundation

Anyone have a particular favorite?

Ideally I'd like to give money to a non-profit that would foster some of the smaller but promising open-source and/or free software projects. The big projects like Firefox and Apache are already well-established. There are a few small individual shareware programs I've already paid for directly. But it's those middle-ground projects that I would really like my contributions to support. (one that comes to mind is a good GUI for Subversion or Mercurial.)

It's one thing for a single person to donate a little $$ to a small project. It's another for a foundation or something to give larger grants to projects that give a good bang for the buck. Conservation organizations like The Nature Conservancy, or the Trust for Public Lands, have really honed this approach, but I'm not really sure if there's an equivalent model in software-land.