I know you're always always in the middle of doing something with HTML, js and CSS, but want to use real server-side paths. I know how it bothers you to set up Apache, nginx, IIS, SOMETHING, just to see your pages and apps blossom. volna lets you run a server for a given path on a fixed port, no sweat. You're left with the clackety sound, now.
Gemfile gem 'volna', '~> 0.1.0'
install gem install volna -v 0.1.0