1970s: Lisle, Illinois-based Pansophic Systems offered PANVALET, which was an early source code control system for the mainframe market.[2] 1975: Professor Pressor's work eventually grew into a commercially available product called Change and Configuration Control (CCC) which was sold by the SoftTool corporation. Revision Control System (RCS, Walter Tichy). Early 1980s: patch (around 1985, Larry Wall).