HALMD is maintained in a public Git repository at
git://git.colberg.org/research/halmd
In case you are behind a firewall that blocks the git protocol port, use
http://git.colberg.org/research/halmd
If you are new to Git or version control in general, the Git tutorial will get you started.
Former Subversion users may also read the Git SVN Crash Course.
For in-depth documentation, see the Git User’s Manual.