A dedicated parallel solver in C++ is available at:

https://github.com/ciaranm/parasols

Implementations of several algorithms in Java are available at:

http://www.dcs.gla.ac.uk/~pat/Downloads.html

Implementations of a particular algorithm in several languages are available at:

https://github.com/ciaranm/sicsa-multicore-challenge-iii

File	Type	Notes
naive-maxclique.essence	Essence
naive.mzn	MiniZinc
Clique.py	PyCSP3