par2cmdline is a PAR 2.0 compatible file verification and repair tool.
To see the ongoing development see: https://github.com/parchive/par2cmdline
OpenMP multithreading was originally developed by Jussi Kansanen: https://github.com/jkansanen/par2cmdline-mt
The original development was done on Sourceforge but stalled.
For more information from the original authors see http://parchive.sourceforge.net
This is also the place for details on the PAR 2.0 specification and discussion of all things PAR.