
We applied for GSoC in 2008, but didn't make it for several reasons. In 2009 we were more successful and have been accepted as a mentoring organization!
The Google Summer of Code is a program designed to encourage college/university student participation in open source development. Students in Computer Science or related fields are provided the opportunity to do work related to their academic pursuits during the summer. To achieve this Google pays students stipends to work on open source projects like TYPO3.
A lot more information is available in Google's Summer of Code FAQ and Knowledge Base.
First organizations like the TYPO3 Association sign up as mentoring organizations for GSoC. If the organization gets accepted students submit project proposals to the organization. We then rank the submissions and pair the students with mentors from the TYPO3 project.
Google then allocates a given number of slots to each organization and the students work all summer on their project in close mentored collaboration with that organization.
A program stipend paid by Google allows students to concentrate on their Open Source Software development project.