(I'm one of the folks who look after the Tux4Kids apps - Tux Math, Tux Typing, and Tux Paint)
First of all, as a GSoC participant since 2008, Leslie rocks!
Second, I am really amazed at the impact of GSoC in proportion to the resources expended on it by Google. Our projects have gotten a big boost from GSoC, and I think the experience has been similar for others. It is quite amazing to consider that GSoC really has been a one-woman show, with the help of a modicum of funding from Google.
It reminds me of the saying attributed to Archimedes - with a long enough lever (FOSS) and a suitable fulcrum (Google), one (wo)man can move the world.