How to create a Ruby gem with Bundler Bundler is a tool created by Carl Lerche, Yehuda Katz, André Arko and various superb contributors for managing Rubygems dependencies in Ruby libraries. Bundler 1.0 was released around the same time as Rails 3 and it’s the Rails project where Bundler is probably most well-known usage occurs. But remember, Bundler isn’t just for Rails! Did you know that you can