Can this be used with ruby (not on rails)?

[jagill]

I don't see anything obvious in the documentation, but maybe I'm just missing something?

To be clear, I'm using a pure ruby script, no rails, no server, nothing for the browser to point to. But i'd love to debug it in vim!

[astashov]

This is in Vim doc, https://github.com/astashov/vim-ruby-debugger/blob/master/doc/ruby_debugger.txt#L141 :)
Just don't forget to put a breakpoint before running the script, of course, since it will start to execute immediatly after running.