PRCS is an attempt to provide a version-control system for collections of files with a simple operational model, a clean user interface, and high performance. PRCS is characterized by the use of project description files to input most commands, instead of a point-and-click or a line-oriented interface. It employs optimistic concurrency control and encourages operations on the entire project rather than individual files. Although its current implementation uses RCS in the back-end, the interface completely hides its presence. PRCS is free. This paper describes the advantages and disadvantages of our approach, and discusses implementation issues.