TFM

TFM is a tool for searching and viewing Mac OS X documentation and source code: Apple's documentation, system framework headers or /usr/include, the Examples source and your own code.
Since it parses C and ObjC, HTML, RTF, and Apples Java documentation, TFM is able to generate class diagrams, lookup method definitions and provide other developer-oriented abilities not possible in a Web browser, HelpViewer or other file "grepping" programs.