Google Summer of Code has been around since 2005. In the program, Google partners with open source software projects and technology-based groups to fund students interested in working on real world software development for three months. Students gain good experience and advice from mentors. The organizations get specific projects or features developed while increasing the developer base for the open source community.
Students 18 and older are able to apply for Google Summer of Code projects and over 1,000 students participate each year with hundreds of organizations from around the world. Google provides a $5,500 stipend to the student developer.
You can learn more about Google Summer of Code from the GSoC page on Google Developers. The site offers a timeline of Google Summer of Code, history, rules, and other resources.
Most interesting, in my opinion, you can view the accepted projects that have a student and mentoring organization assigned. You can see the 1,205 projects being worked on with 178 open source organizations. View the full list of projects that the student are working on with Google Summer of Code 2016 and look forward to the enhancements in some of your favorite open-source projects including Python, GNU, R, jQuery, Wikimedia, KDE, ownCloud, and many more.