Getting Started with the Tribler source code
Tribler is based on the ABC client which in turn is based on Bittornado which in turn is based on Bram Cohen's original Bittorrent client. The source code of Tribler is publicly available under a LGPL Open Source license.
You can get the source from the download page or directly from our Subversion repository. If you just want to sneak a peek, you can also simply browse through it.