HLP (WinHelp)

Description
WinHelp is a help file format based on RTF created by Microsoft that exists in several versions and was used in Windows 3.0 up to Windows 95 and NT. Starting with Windows Vista, the format can not be opened without additional software downloads. The format was abandoned to encourage use of the newer CHM (compiled HTML) help format.

See alson

 * CHM

Resources

 * Wikipedia article
 * Resource page for Windows help formats
 * Subpage on the site linked above with a list of links to software and information about the WinHelp format