While Foreman is written in Ruby, you don't actually have to use it in any way that is connected to a Ruby or Rails app. All you need is a Procfile and the foreman gem installed on your system.

Then, you can run the processes in the foreground with `foreman start` (eg. on your dev machine), or export the processes to config files for the init system of your choice (eg. on your server). Once the processes have config files in the init system, Foreman is out of the picture: your processes are run and managed by the init system.

Of course, this all works very well in a Rails app (hence my blog post), but that's only one of many uses. Hope that helps!

As far as I know you can run anything with it, not just ruby apps.