Files with .stn extension are often Genuine Fractals Image files. This format allows images to print big and scale without quality loss. It was originally a Photoshop plugin.
Programs that support .stn files include ArcView. ArcView was created by Esri to handle ArcView Geocoding Standardization files.
255 extensions are listed as .stn. But most are not compatible. Files must be converted to other formats to use.
.stn files belong to GIS category. ArcView is the most common .stn file program. Check Esri’s site for details.
Other .stn uses are audio and templates. Methods to open them vary.
Usage is highest in the US with Windows 10. Google Chrome is the popular browser.