Joanna Glasner has written an overview of the program:

When Narayan Newton, an Oregon State computer science student, received an e-mail from a prominent developer of Linux desktop applications, he expected it to be a complaint. “I’d submitted some bug reports,” he says. Instead, Newton was surprised to learn that the programmer, Duncan Mac-Vicar, would be his personal mentor for three months, courtesy of Google’s “Summer of Code” program.

The program, now in its second summer, pays 630 students to stay home and code over the summer, working under mentors that include more than a few rock stars of the open-source world. “A lot of times in computer science school you’re exposed to important problems, but you’re not exposed to what’s on the other side of the keyboard,” said Chris DiBona, Google’s open-source program manager, discussing the program at this week’s O’Reilly Open Source Convention here.