| gwl | Photonic Professional GWL Data |
| gwp | GoodWay Flight Plan Data |
| gws | Groundspeak Wherigo Save File |
| gwt | AquaCrop Groundwater Data |
| gwt | GeoDa Distance Weights Data |
| gwt | SpaceStat Generalized Weights Format Data |
| gwv | Groundwater Vistas Packaged Model |
| gwx | Genigraphics Graphics Link Presentation |
| gwy | Gwyddion Surface Data |
| gwz | Genigraphics Graphics Link Presentation |
| gwz | Groundspeak Wherigo Cartridge Archive |
| gx | GenX Data |
| gx1 | CCSM-POP Greenland Pole X1 Grid Data |
| gx2 | General CADD Pro Image |
| gx3 | CCSM-POP Greenland Pole X3 Grid Data |
| gxa | General CADD Attribute Data |
| gxb | GP32 ROM Image |
| gxc | General CADD Pro Component |
| gxh | General CADD Pro Hatch |
| gxkey | GameEx Registy Data |
| gxl | Graph Exchange Language |
| gxm | General CADD Pro Macro |
| gxml | Guideline XML Data |
| gxs | GrafiXML Graph |
| gxv | General CADD Pro Menu |
| gxy | ISIS GIS Visualiser Schematic Data |
| gyg | Gygan Data |
| gym_zip | eXtendable Wad Editor GYM_ZIP Data |
| gz1 | Orgadata LogiKal Data |
| gzf | WebCopier Data |
| gzl | Go!Zilla File List |
| gzmat | Gaussian Z-Matrix Chemical Modeller Input Data |
| h | Miranda IM SmileyAdd Plugin |
| h00 | Flash ROM HEX File |
| h01 | Flash ROM HEX File |
