The module was written as a low-dependency proof of concept for something to be run behind nginx 1.2 (the one shipped in Debian Wheezy), later extended to be a little more generic (i.e. parametrized).
Example code, including HTML and snippet of nginx.conf, is supplied in the documentation for the application.
How to download
git clone http://dozzie.jarowit.net/code/erlang-mod_sse.git
How to install
Installation process is tested for building RPM/DEB packages. If you want to make mess in your system by omitting package system, you are on your own. The application, however, uses rebar to build its code, so it should be pretty standard as for Erlang.
You need casual package building tools for your distribution, either rpm-build (RPMs) or dpkg-dev with fakeroot (DEBs). For Debian, you'll also need dh-rebar (Debian package for Jessie and my backport for >=Squeeze, including source package).
The process boils down to run rebar compile. *.beam files will be stored in ./ebin directory.
The EDoc documentation can be generated using rebar doc.