Sinatra is a free and open source software web application library and domain-specific language written in Ruby. It is an alternative to other Ruby web application frameworks such as Ruby on Rails, Merb, Nitro, and Camping. It is dependent on the Rack web server interface. It is named after musician Frank Sinatra. Sinatra was created and open-sourced in 2007. It inspired multiple ports and similar projects in other programming languages, such as Express.js and Scalatra. Mizerany and Heroku's Adam Wiggins introduced and discussed Sinatra at RubyConf 2008.