Eclipse is an open source code base, and has been written by thousands of individuals across the years. The Eclipse Foundation are the stewards of the code, but the foundation staff themselves are few in number and generally do not write the code for Eclipse itself; rather, they look after the ancillary services (bug tracker, git and Gerrit source code repositories, news groups, wiki, and website) and the EclipseCon and DevoxxUS conferences around the world (http://eclipsecon.org, http://devoxx.us). There are commercial companies who build their products on Eclipse and contribute to the underlying platform, but there are many open-source volunteers who contribute their time and effort to improve Eclipse. This chapter will show you how you can make a contribution to Eclipse by checking out a repository, raising a bug, and filing a patch.