Debian

Preferred license: GNU General Public License (GPL)
Debian is a free operating system (OS) for your computer. An operating system is the set of basic programs and utilities that make your computer run. Debian uses the Linux kernel (the core of an operating system), but most of the basic OS tools come from the GNU project; hence the name GNU/Linux.
Actual source code produced by the student participants in Google Summer of Code™ for Debian can be found here.
 
Current Projects
by Jeroen van Wolffelaar, mentored by Martin Michlmayr
by Ian Haken, mentored by Lars Ivar Wirzenius
by Ana Beatriz Guerrero López, mentored by Luk Claes
by Cameron Dale, mentored by Anthony Towns
by Gustavo Rezende Montesino, mentored by Loïc Minier
by Margarita Manterola Rivero, mentored by Stefano Zacchiroli
by Pavel Vinogradov, mentored by Javier Fernandez-Sanguino
by Martín Hernán Ferrari, mentored by Steve McIntyre