The releases are still in alpha-development at this time, though we are very close to a beta-release of the stand-alone module. You can check the status of that at this page but there will also be updates on the front page for this particular project when the time comes.
There is currently a release of version 0.1 of the software. The build process is not fully in place (with any sort of autotools-like build), however the basic Makefile in the files should be enough to build the system on Linux, Mac OS X or Solaris (and likely other BSDs as well). If you encounter problems with it, you can report them on the mailing list. To build it you will need libpcap and the netinet headers for your platform installed into pretty normal locations (/usr or possibly /usr/local depending on your compiler configuration) and you will need gcc. Hopefully a future version will build with some of the familiar auto-building tools.
If you wish to get your hands on the source while we are working out the bugs and preparing for a realease, you can find the information on how to acquire a copy of the source code on this page.