| glz | Crossword Power Tools Grids Library |
| gm1 | Gerber Mechanical Layer 1 Data |
| gm2 | Gerber Mechanical Layer 1 Data |
| gm3 | Gerber Mechanical Layer 1 Data |
| gm3 | SAPS File |
| 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 |
| gmf | SmartWare Pre 1.5 Graph Metafile |
| gml | Girder Plugin |
| gmmod | Game Maker 3D Model |
| gmr | Schlafhorst Graphical Monitor Record |
| gmres | Game Maker Resource |
| gms | GAMS Model File |
| gms | Gesture and Motion Signal Format Data |
| gmspr | Game Maker Sprite |
| gmt | GenePattern Gene Matrix Transposed File |
| gmx | GenePattern Gene Matrix File |
| gmy | HemeLB Geometry Data |
| gna | Genigraphics Graphics Link Presentation |
| gnc | Great Notions Embroidery Data |
| gnet | PJM GNET Data |
| gnf | GluonPilot Navigation File |
| gni | VisiDAQ Data File |
| gno | GenoPro Genealogy Tree |
| gnp | GNPeak Output File |
| gns | Sound Health Abacus Genesis Data |
| gnucash | GnuCash Financial Data |
| gnx | Genigraphics Graphics Link Presentation |
| gnx | GNPeak Numeric Output File |
| go! | Go!Zilla Unfinished Download Data |