The PostgreSQL source code is managed using
GIT, which was originally developed by Linus Torvalds for the Linux kernel source. Many associated PostgreSQL projects now also use
Originally, PostgreSQL used
CVS for source control, and migrated to
GIT in 2010 .
The PostgreSQL GIT repository can be cloned with:
git clone git://git.postgresql.org/git/postgresql.git
No password or authentication is necessary. On a fast connection with an average download rate of around 6MiB/s, it took about 60 seconds to clone the entire repository.
A cloned repository can be updated to the latest version using:
 "Lessons from PostgreSQL's Git transition" - https://lwn.net/Articles/409635/