Free Hero Mesh composite puzzle set
From Just Solve the File Format Problem
A Free Hero Mesh composite puzzle set file is a Hamster archive containing the other four files of a Free Hero Mesh puzzle set, and optionally some additional lumps, such as FILE_ID.DIZ.
Note: Free Hero Mesh doesn't care about the file name of a composite puzzle set; the use of .fhm is a convention used by some people.
The main four files have names with the correct suffix, although the part of the name before . can be anything and need not match the file name of the composite puzzle set, nor are they required to match each other (although they usually do).
There is supposed to be the possibility to optionally compress lumps with Quasijarus Strong Compression, although this feature hasn't been implemented.
