Volt - Volt is a reactive web framework where Ruby code runs both on the server and the client (via opal).
Cuba - Cuba is a Ruby microframework for web development.
Calm Radio - Calm Radio is a music streaming alternative that offers calming music. Listen to classical and relaxation music for work and sleep, online jazz music with nature sounds, meditation and world music available on our Calm Radio app.
Ramaze - Ramaze is a very simple and straight-forward web-framework.
Padrino - Padrino is a Ruby web framework built upon the Sinatra web library.
NYNY - A (ridiculously) small and powerful web framework.