Currently, there are four PyMOL plugins available:
Azahar extends the PyMOL's capabilities to visualize, analyze and model glycans and glycoconjugated molecules.
Optimize allows energy minimization of molecules.
Cheshift provides a way to use the familiar enviroment of PyMOL to validate a protein model, using CheShift-2 server.
Dehydron calculates dehydrons and display them onto the protein structure.