DistributedSourceControl software.

Takes some getting used to, but good once you get it. Now pretty much the default option. Particularly due to the success of GitHub.

I'm involved in a debate / argument with JonathanEdwards and others over at https://mobile.twitter.com/jonathoda/status/1315795489695043584

Read the thread.

See Gitless for some research into simplifying git through ConceptPurposeAnalysis