Written in C, the code's latest version, CitComS, runs on a variety of parallel processing computers, including shared and distributed memory platforms.

Consequently, the fundamental finite element infrastructure which Louis wrote is still in place and forms the basis for much of the code contained in the present release.

Then Shijie Zhong (U. of Colorado, Boulder) successfully parallelized CitCom using message passing routines on a limited release Intel supercomputer.

By 2004, in order to increase the functionality of CitComS, the developers began to reengineer the code into an object-oriented environment specifically so it could work with a Python-based modeling framework called Pyre.

Other improvements included the incorporation of geoid calculations that had been left out of earlier releases, as well as new scripts to allow results to be visualized with MayaVi2[5] in addition to Generic Mapping Tools (GMT)[6] and OpenDX.

It can be used in tracing the trajectory of passive particles, in delineating the top boundary of subducted slabs to define the low viscosity wedges, or in tracking the evolution of the chemical composition field.