> Can anyone tell me which MM.NET files will need to be installed on the web server? I didn't install any on my test server, which is my development machine, and everything worked, but maybe that's because they MM.NET stuff has somehow been registered with Windows?

Correct. Open Web.Config file in your project. Under tag < assemblies > you'll find all Mere Mortals assemblies required to run the web site. Each assembly name corresponds to a folder in ...\Program Files\Mere Mortals... Each source folder among other files contains a DLL file.

...\Program Files (x86)\Mere Mortals...
for 64-bit OS