I've released a new .vtf utility today, this time it is a Photoshop .vtf file format plug-in. This plug-in will allow you to open and save simple .vtf files through Photoshop using VTFLib. You can download the plug-in and find more information here.
Why donīt you make a plugin for the IrfanView program?
The plugins system works similar to the Photoshop system and this is one of the best image viewers out there.
If you want to make the plugin you should contact them as they say:
For developers: If you want to write your own plugins for IrfanView (support for new image formats), please send me an email for details.
New users can register here.