QuickHelp file
File type: Various data file
An .altp file is a QuickHelp file used by QuickHelp for Mac.
It stores data used by the QuickHelp application for a help document or project.
File type category:
Various data file
Date updated: September 24, 2026
The ALTP file extension identifies a proprietary data file associated with QuickHelp for Mac. QuickHelp is help-authoring software for Apple macOS and Mac OS X.
An ALTP file is intended to be used by QuickHelp rather than opened as a general-purpose document. Its contents belong to the QuickHelp project or help document with which it was created.
Open an ALTP file with QuickHelp for Mac on Apple macOS or Mac OS X. Use the application's Open command and select the file.
Because the format is application-specific, other programs may not be able to read it correctly.
Open the file in QuickHelp for Mac and use any export or publishing options provided by that application to create a different output format.
Software applications that handle other tasks involving altp files:
Apple macOS / Mac OS X
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