If you're looking at this on GitHub, the master repository is actually here: https://foss.heptapod.net/Omnifarious/StrMod
OK, you've downloaded this thing, now what?
The first thing to do would be to build it. This builds with CMake and there are two major targets. The Net target, which builds the shared library, and the PortForward target, which builds an example program.
Eventually, there should be tests. Though, I've been saying that for a very long time. Also, I should make this so it can easily be installed and worked with by programs that depend on it. This includes being installed by a Linux distribution's package manager, but it also includes being a sub-repo in Mercurial or git and being able to depend on it from the main repo.
Also, I really need to add a Doxygen target for all of this.
Anyway, I hope this is enough to get you started. Feel free to come onto irc at irc.freenode.net, channel #StrMod and ask questions.