The STARS simulator everyone refers to as ATCoach is actually named the Test and Training Simulator Equipment (TTSE), or SIM for short. In STARS TIs, it is usually listed as TTSE (SIM).
ATCoach is the software that runs the simulations and was developed by UFA, Inc. And that is why TTSE SIM files are normally found in the UFAatpro file at the SSS or GPW.