 Specifically CVS (Concurrent Versions System) was developed on top of RCS structure, improving scalability of the tool for larger groups, and later branched out PRCS as a simpler CVS-like tool.Nowadays, Subversion may be considered as the most popular and widely in use VCS tool from this generation which has filled important weaknesses of CVS.Later SVK developed with the goal of remote contribution feature, but still the foundation of its design were pretty similar to its predecessors.