From my point of view this is primarily a historic artifact, with limited practical use. As I mentioned in another comment, my projects (at Sun in the 1980s and

From my point of view this is primarily a historic artifact, with limited practical use. As I mentioned in another comment, my projects (at Sun in the 1980s and 1990s) used SCCS on shared filesystems. For day to day work everything has long since moved to other VCSes such as Git and Mercurial. The JDK sources were maintained in SCCS (which was wrapped within CodeManager/Teamware) prior to being open sourced in 2007. The history in the OpenJDK repositories goes only back to that time. The (Oracle internal) archives of previous versions of the JDK, which date to before JDK 1.0, are still in SCCS format. I'll occasionally browse through the ancient history of these sources using Schily's SCCS implementation. What's cool is that all my old shell aliases and functions still work. Of course this is browsing/viewing only. I haven't checked in an edit using SCCS in decades.