An hhh file extension is related to the Power C compiling tool. An hhh file stores precompiled header data.
HHH file extension - Power C precompiled header data
What is hhh file? How to open hhh files?
File type specification:
The hhh file extension is related to Power C compiler and used for files that contain precompiled header.
Power C was an ANSI compatible C compiler for DOS.
Most likely some old format without support. No further information could be found.
This hhh file type entry was marked as obsolete and no longer supported file format.
This type of file is no longer actively used and is most likely obsolete. This is typically the case for system files in old operating systems, file types from long discontinued software, or previous versions of certain file types (like documents, projects etc.) that were replaced in higher versions of their original programs.