# HTML Help processing

The htmlhelp transformation creates HTML Help control files. If the build runs on a system that has the HTML Help compiler installed, the control files are compiled into a CHM file.

Once the pre-processing and XHTML processes are completed, most of the HTML Help processing is handled by the following targets:

`dita.map.htmlhelp`
  Create the HHP, HHC, and HHK files. The HHK file is sorted based on the language of the map.
`dita.htmlhelp.convertlang`
  Ensures that the content can be processed correctly by the compiler, and that the appropriate code pages and languages are used.
`compile.HTML.Help`
  Attempts to detect the HTML Help compiler. If the compiler is found, the full project is compiled into a single CHM file.