.HMXP File Extension
File TypeHelp & Manual XML Project
What is an HMXP file?
XML project file created by Help & Manual, a program used for creating help documentations; saves references to project files as well as project settings, but does not store the referenced project assets, such as images; differs from .HMXZ files, which store all assets in a single archive.
NOTE: HMXP files were introduced with Help & Manual version 5.