The Ruby Explorer is a class browsing tool which can be used to view an alphabetical outline of Ruby classes and methods. The Explorer shows the classes of the standard Ruby library plus the classes defined in the current project. The methods of each class can be viewed by clicking the + symbol to the left of the class name.
You can double-click a class or method name in order to navigate to its source code (if available) and any embedded documentation. Much of Ruby's class Library is written in the C language; in these cases, the Ruby Explorer will load up a Ruby documentation file which has been generated from the original C file and it will navigate to the documentation relating to the selected class or method.