HeaderDoc is a documentation generator developed and maintained by Apple Inc.
The HeaderDoc tool set consists of the main utility, headerdoc2html, and gatherheaderdoc.
Afterwards, the gatherheaderdoc utility may be executed to create a table of contents file for the documentation.
Finally, the resolveLinks utility may be used to resolve cross-references between multiple documentation collections.
Apple's Xcode development environment contains features designed to assist the process of creating documentation using the HeaderDoc syntax and tools.