dusen Show archive.org snapshot 0.4.8 and edge_rider Show archive.org snapshot 0.2.3 no longer depend on Rails (they still depend on ActiveRecord). That means you can use them e.g. with Sinatra.

Rails Long Term Support

Rails LTS provides security patches for old versions of Ruby on Rails (2.3, 3.2, 4.2 and 5.2)

dusen and edge_rider gems no longer depend on Rails