The code uses Qt library. To develop, you need Qt 4.8.1 or later, for Mac OS, using Qt5.5.1 is recommend., do not use Qt5.5.0, it contains an ugly bug. SVN is used to manage development and SourceForge Tracker to keep track of bug reports and feature requests. All classes are documented using Doxygen.
For a long time, ChessX was pushed forward by Michal Rudolf.
Currently, there are two active ChessX developers: James Coons and current maintainer Jens Nissen. The main tester and usability expert is Bruno Rizzuti.
Among inactive developers we would like to mention Marius Roets, Sean Estabrooks, Rico Zenklusen, William Hoggarth and Ejner Borgbjerg who wrote significant parts of code. Heinz Hopfgartner made useful tests and maintained Mac port.
If you wish to participate in the project (either as a developer or a tester), please sign up to the developer mailing list and introduce yourself.