This is a demo of Glimmer DSL for Web without the need to run inside a rails app or any app. It is usable in a static site. Rails is currently still a dependency because opal-rails is included in glimmer-dsl-web, but it is technically not necessary.
Make your changes to script.js.rb
bundle install
ruby app.rb
Then open index.html.
For your convience, I included filewatcher.rb which can be used to automatically regenerate the javascript file on edits to the code.