grSim was originally developed by Ali Koochakzadeh and Mani Monajjemi from Parsian, the RoboCup Small Size Team of Amirkabir University of Technology. Since 2011, it has received numerous contributions from the RoboCup SSL community as well as Parsian team members (listed below). grSim is Currently maintained by Mohammad Mahdi Rahimi.
- Christopher Head - Thunderbots (University of British Coloumbia)
- Jonathan Fraser - Thunderbots (University of British Coloumbia)
- Verónica Raspeño - University Carlos III of Madrid
- Alejandro Caparrós - University Carlos III of Madrid
- Jan Segre - RoboIME
- Henrique Bonini de Britto Menezes - Universidade de São Paulo