This is a Ruby tree! It shows every object from the Ruby Programming Language in a tree format.
# Gem::UnsatisfiableDependencyError.dependency (from ruby core) --- The unsatisfiable dependency. This is a Gem::Resolver::DependencyRequest, not a Gem::Dependency
This is MURDOC! A Ruby documentation browser inspired by Smalltalk-80. It allows you to learn about Ruby by browsing through its class hierarchies, and see any of its methods.