FAST Piper is a gas pipeline, wellbore, and reservoir deliverability model. It is a piece of software developed and supported under Microsoft Windows operating systems. Piper is a beautiful piece of software for modeling gas gathering systems. It deals with critical issues such as multi-phase flow, compressors, contracts, rate limitations, multiple wells, multiple pools, and gas composition tracking.
I've used this software, and I must say it is incredibly nice. It has a wonderful user interface, and it does just about everything a guy could hope for in a gas gathering model. It is a revolutionary and unique piece of software. I may be bais since I work for the company, but hey.. whatever. :-)