XT* file extension is for Crosstalk Related File
Similar to XT*
3DMF - QuickDraw 3D Metafile QuickDraw3DS - Graphics Autodesk 3D Studio
3FX - 3D effects CorelChart
3gp - Video format compatible with mobile devices
3GR - VGA graphics driver Windows Video grabber
3T4 - Util3 Binary file converter to ASCII
4C$ - 4Cast/2 Datafile
View all in File Extensions