Look at the "widely used and accepted" section of the above page
I found much more about such systems by googling for
open source version control systems
It's like a jungle of new and old systems out there, maybe better to
first decide if you like personal control over your program, or to make
it open source.
Then talk to other programmers about how to do it for that type of
licence.
It is no hurry, take your time and investigate the alternatives.