Google Summer of Code
We have been involved in 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 and 2014; in 2006, 2007, 2009, 2010 we had lots of students, most of whom achieved something of value, and a few of whom became volunteer developers for Freenet. In 2008, we had only one student, who failed because of external issues.
If you want to apply, please join us in IRC and start by contributing a bug fix or minor feature.
Students will be required to communicate publicly on the mailing lists — at least with weekly progress reports — and where appropriate via IRC, the wiki and so on. Your mentor is there for you, but talking only to your mentor is inefficient and doesn't result in being part of the project community. We want to treat you as a developer (which means a valued volunteer), while giving whatever help is possible and needed.
To succeed in your project, you will have get it released, so plan small enough.