YARD, is an embedded documentation generator for the Ruby programming language. It analyzes the Ruby source code, generating a structured collection of pages for Ruby objects and methods. Code comments can be added in a natural style.
YARD is useful even if the target source code does not contain explicit comments. YARD will still parse the classes, modules, and methods, and list them in the generated API files.
YARD extends upon the capabilities of RDoc in a number of dimensions:
Dan Kubb has created an ancillary tool, named Yardstick, which verifies YARD (or RDoc) documentation coverage.