"Let's say you want to write a GPLed online card game, like bridge, in C. And wanted to see how others had handled shuffling the cards. On the Koders.com site, you could search for 'shuffle cards' with the license option set to GPL and the language set to C. Then click on the Search button.
"The results screen shows one hit: a program called server.c from the UNO - Card Game project on SourceForge..."