Yes, OpenBSD invented anonymous CVS which was the first way to access a version control system without prior authorization http://www.openbsd.org/papers/anoncvs-paper.pdf

It was already ubiquitous in 1997 when I got started working on open source software, so I took it for granted. I was surprised to find out 20 years later how new anoncvs had been and how fast it spread to other projects like FreeBSD and Apache httpd.