The Early History of GNU CSSC
Ross Ridge wrote MySC, a public domain version of SCCS that compiled with early versions of the GNU C++ compiler. Having long thought that there were no free versions of SCCS I downloaded this the moment I found out about it. Unfortunately it no longer compiled with the version of GNU C++ that was then current. I fixed this and tried it out. I found that although MySC represented a great deal of work, there was lots of functionality of SCCS that was missing, and what had been implemented wasn't always quite compatible with SCCS.
I offered to collaborate with Ross Ridge to improve MySC but he appeared not to be interested in the amount of work this would involve. This is quite reasonable of him; he had generously put his work in the public domain and he indicated to me that he had released it into the public domain in order not to be constantly bothered by people wanting support and so on.
With no support from the original author I had the choice of doing the work myself or giving up. I decided to do the work myself, since a working SCCS clone would be of great use to me personally.
I decided to put my own work under the GNU GPL since I have found in the past that in practice this often means that you get help from many enthusiastic hackers and I wanted to give something back to the Free software community since I have benefitted greatly from it.