SumatraPDF is a multi-format (PDF, EPUB, MOBI, FB2, CHM, XPS, DjVu) reader for Windows under GPLv3 license, with some code under BSD license. The main source repository is at http://code.google.com/p/sumatrapdf/ A read-only git mirror is at https://github.com/kjk/sumatrapdf Want to join the project and contribute code? Read https://code.google.com/p/sumatrapdf/wiki/JoinTheProject To compile you need Visual Studio 2008, 2010 or 2012. Open the right solution from vs directory.