monodevelop

Clone their repository from git (tarballs created by them fail way too often)

git clone https://github.com/mono/monodevelop.git

If you created and compiled unit tests using MonoDevelop you need to copy several dlls to the same directory before you can use nunit-console with compiled dll. Those libraries can be found /usr/local/lib/monodevelop/AddIns/NUnit directory