This plugin allows Adobe® Photoshop® 5.0 or later to load and save Fsh files.

Images containing an alpha channel are handled differently depending on the version of Photoshop.
Photoshop 5.5 or earlier will add the alpha channel to the channels palette.
Photoshop 6.0 or later will use the alpha channel as the layer transparency.

The installation instructions are in the Readme.

The support thread is Fsh Format Plugin for Adobe® Photoshop® The source code is on GitHub: https://github.com/0xC0000054/FshFormat