Pry is a runtime developer console and IRB alternative with powerful introspection capabilities. Pry aims to be more than an IRB replacement. It is an attempt to bring REPL driven programming to the Ruby language.

ripl is a light shell that encourages common middleware for shells i.e. rack for ruby shells. It is also a modular alternative to irb. Like irb, it loads ~/.irbrc, has autocompletion and keeps history in ~/.irb_history. Unlike irb, it is highly customizable via plugins and supports commands i.e. ripl-play. This customizability makes it easy to build custom shells (i.e. for a gem or application) and complex shells (i.e. for the web). Works on ruby 1.8.7 and greater.

A Ruby REPL inspired by the Fish shell

Ruby-Interactive-ruBy -- Yet another interactive Ruby shell Rib is based on the design of [ripl][] and the work of [ripl-rc][], some of the features are also inspired by [pry][]. The aim of Rib is to be fully featured and yet very easy to opt-out or opt-in other features. It shall be simple, lightweight and modular so that everyone could customize Rib. [ripl]: https://github.com/cldwalker/ripl [ripl-rc]: https://github.com/godfat/ripl-rc [pry]: https://github.com/pry/pry