The application is a part of Zerg demo (http://try.erlangonxen.org/zerg).
Before use the application must be converted into a Xen image using an Erlang on Xen build service (http://build.erlangonxen.org).
Use the following command to make the image:
rebar ling-build-image
You may need to plug your build service credentials to rebar.conf. The image should be copied to Dom0 for libvirtd to be able to find it.
Makefile and zergling.xml files are needed for testing only. The 'spawnpool' application generates a domain configuration file on the fly (see https://github.com/maximk/spawnpool).