Fifty Years of Software Development

Jeff Atwood’s blog post Fifty Years of Software Development use’s O’Reilly’s History of Programming Languages poster to show how we’ve been at this programming stuff a long, long time but that the profession of software development is still very much in its infancy.

I like much of what Jeff has written but I take issue with his contention that source control was not widely prevalent until 1999. He goes on to qualify this statement and say that source control wasn’t in mainstream use until then. I’m not sure how to quantify “mainstream” usage but I used source control systems for many years before 1999. At companies large and small. In some cases the source control system was built in-house. In fact, I wrote the one we used at my first startup back in the mid-80s.

While I wouldn’t want to live without CVS, Subversion, etc., source control can be more basic. At Iris, the early versions of Notes were developed with crude source control tools. Each developer had the entire source pack on their machine. Whenever they were about to modify a file, they took a snapshot as a “point of divergence” (aka POD). When it came time to submit changes, they ran a tool called “pmerge” that would do the three-way merge from their POD, the current checked-in code and their changes. The result of the merge would become the new version. Changes were then recorded in a “one liner” file. Very crude but it worked. Just before I started at Iris, part of this manual process was replaced by PVCS and then (gulp!) entirely by Clearcase.