mod plugins are specialized lv2 plugins. So, by on the desktop, I meant installing it as an lv2 plugin on my desktop machine and running like
% jalv.gtk http://dsheeler.org/plugins/harmonizer
On my desktop, I'm running linux and using jack, jalv is a simple plugin host for jack so basically this creates an interface to tweak parameters and it has a jack input and midi output. Maybe check it out again on github, there's now a short readme with how to build (make) and install (make install).