From CVS to Git, thirty years of source control

Also a note about a specific bias from old-heads:

At the start things move much faster and changes are more impactful, but the start is ultimately much shorter than the rest of the lifecycle. That's why a lot of the stories you read about tech are about the early years (let's say 5-10 years, chronologically) and less so about the mature years (which can span 3+ decades, chronologically). So the early period has outsized visibility because it's cooler, I guess?

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Using SCMs as an example:

SSCS - 1972. But at that point there was no internet and the number of computer users was minuscule. So SCCS is just a curiousity, a footnote, probably used by 0.000001% of Git users. So at this point for most practitioners SCMs basically don't exist.

RCS - 1982. See SCCS. SCMs still practically don't exist for most practitioners.

CVS - 1986. Now the internet is getting started and the number of computers in the world has increased by orders of magnitude. Even so, adoption of core development technologies like SCMs is slow and yes, it took CVS at least 10 years to become somewhat established. Even at this point, probably at least 50% of software developers still don't use SCMs (especially less professional ones). Visual Source Safe runs in parallel to CVS, with its own problems described in the article.

SVN - 2000. The internet is in full swing, computers are ubiquitous, things are really moving. It's super hard to evaluate how many developers still don't use SCMs, but the number is going down (maybe 30-40%?) and SVN is taking the world by storm. Even after the launch of Git in 2005, until at least 2009-2010, SVN had a solid shot at winning. It's tooling was much better, especially the GUIs, TortoiseSVN & co.

Git - 2005. Git is launched in roughly the same era as SVN, just towards the end. Once Github gets going it starts to take over the SCM scape, primarily from SVN, sometimes from CVS, Perforce, and also from non-SCM people.

So, if you look at the real dates implied above: CVS, SVN, Git are widely adopted in about a 10-12 year span (something like 1998-2000 to 2008-2010). Then we reach the current mature (monoculture?) stage where we're already at least 16 years in and it's quite likely this phase will last decades.

This story has happened for lots of tech. Many different PC OSes during the 1970-1980s, then basically only 3 since about 30 years - 1995 (Windows, MacOS, Linux).

Many CPU architectures during the 1970-1980s, then basically only 2 since about 30 years (x86, ARM - maaaaybe RISC-V).

FWIW this is how most projects work anyway. And IMO Subversion is still the best VCS when you have a lot of large binaries (the various extensions to Git like git-lfs are just hacks that graft a separate half-baked version control system to it and add further complexity to an already annoyingly complex system). I remember working at a gamedev company in early 2010s and out of curiosity i tried to put everything in the 250GB perforce workspace in a git repository only for git to choke and die before it managed to do anything. In comparison, ~5-6 years earlier i worked briefly at a game porting studio where every single game they had ported (which i'm almost certain went all the way back to the 90s), including all data and source (and these were AAA games, not tiny indie games), were into a single Subversion server.

Unfortunately Subversion lost the VCS fashion wars and nowadays it barely seems to have any development. I still use it for a few projects where i do have a lot of binary stuff, but most new things are in Git. I also have a bunch of stuff in Fossil (which also did handle binary files better than Git when i tested it years ago, though not as good as Subversion or P4) but nowadays i convert them to Git when i need to share because, well, pretty much everyone expects Git (and projects such as Codeberg and Forgejo make sharing and self-hosting easier).

Ironically the "fundamental issue" mentioned above was solved not too long ago with Subversion as nowadays you can have multiple "changelists" and each changelist is a full (hidden) SVN repository by itself, allowing you to do commits (as "shelving") and such locally and then push to remote when you're done. AFAIK changelists can also coexist (unlike Git where you can only work at one branch at each time). Unfortunately since Subversion is basically barely held together, only the command-line UI provides that functionality (at least in FLOSS clients) and even TortoiseSvn didn't seem to support it last time i checked.

Knuth's Tex directory: https://www.saildart.org/%5BTEX,DEK%5D/

It’s probably my memory playing tricks and svn was indeed a short term endeavor.

A great article though!

I kind of "enjoyed" this aspect of CVS (for small teams, at least) since it strongly encouraged trunk based development.

I still use RCS at home for some items and I always liked the locking feature, it avoided lots of issues and it in a way forced changes to be small when using in a team. Plus it forced developers to communicate with each other :) Plus I really like its "$Id$" function when checking in the change.

But I have moved some items to git over the past few years, I like its signing function and on OpenBSD it works with Emacs. RCS on OpenBSD aborts in Emacs unless you install package grcs (GNU RCS) and block OpenBSD's RCS. I only wish git had a built in like "$Id$". I have figured out a work-around but I still would rather have a similar function as RCS has.

At work I finally got people to use git a few years ago, there no one used any form of Source Code Control and it was utter chaos.