Ingen is currently only available in SVN. Since it requires a few libraries in the same repository, it is easiest to:
svn co http://svn.drobilla.net/lad/trunk drobilla-lad
ganv first, then
ingen; or (much faster and easier) build the entire repository (in addition to Ingen, you’ll get Patchage with one build process).
Please support Ingen development:
See the Ingen wiki page for user oriented information.
Please file any bugs you find here