pry

About pry

From Debian's package description

Pry is a powerful alternative to the standard IRB shell for Ruby. It is written from scratch to provide a number of advanced features, some of these include:

• Source code browsing (including core C source with the pry-doc gem)
• Documentation browsing
• Live help system
• Open methods in editors (`edit-method Class#method`)
• Syntax highlighting
• Command shell integration (start editors, run git, and rake from within Pry)
• Gist integration
• Navigation around state (`cd`, `ls` and friends)
• Runtime invocation (use Pry as a developer console or debugger)
• Exotic object support (BasicObject instances, IClasses, ...)
• A Powerful and flexible command system
• Ability to view and replay history
• Many convenience commands inspired by IPython, Smalltalk and other advanced REPLs

From Debian's description of the pry package, under that package's license.