| gmanifest | Google Desktop Gadget Manifest |
| gmax | Autodesk Gmax File |
| gmb | WinDS PRO Data |
| gmbck | Game Maker Background Image |
| gmbl | Vernier Logger Lite Data |
| gme | DexDrive Game Card Image |
| gmf | GameExchange2 Material Data |
| gml | Girder Plugin |
| gmmod | Game Maker 3D Model |
| gmr | Schlafhorst Graphical Monitor Record |
| gmres | Game Maker Resource |
| gms | Gesture and Motion Signal Format Data |
| gms | GAMS Model File |
| gmspr | Game Maker Sprite |
| gmt | GenePattern Gene Matrix Transposed File |
| gmx | GenePattern Gene Matrix File |
| gmy | HemeLB Geometry Data |
| gna | Genigraphics Graphics Link Presentation |
| gnet | PJM GNET Data |
| gnf | GluonPilot Navigation File |
| gni | VisiDAQ Data File |
| gno | GenoPro Genealogy Tree |
| gnp | GNPeak Output File |
| gnucash | GnuCash Financial Data |
| gnx | GNPeak Numeric Output File |
| gocad | GOCAD ASCII Data |
| gof | GameExchange2 RAW Object |
| gold | Gnome Desktop Data |
| gopal | Medion GoPal Navigation Data |
| gosh | GOSH Style File |
| gotmp | Gaussian Z-matrix Template |
| gov | Netmino Data |
| goz | Pixologic ZBrush GoZ File |
| gp1 | Gerber Internal Plane Layer 1 Data |
| gp1 | GamePark.cz Client Data |