| gfo | Grammatical Framework Object |
| gfs | Grammatical Framework Script |
| gfx | The Games Factory Extension |
| ggfx | FactoryTalk View Studio Global Object Display Component File |
| ghc | Adobe RoboHelp Visual Basic Constant Map |
| gitattributes | Git Attributes |
| gitignore | Git Ignore File |
| gld | MPLAB C Compiler Linker Script |
| glnk | TRANSFER Linkage Definitions |
| glo | Visual Basic Global Declaration |
| global | Global Makefile |
| gls | GLScript Game Script |
| glsl | OpenGL Shading Language File |
| gm6 | Game Maker 6.x Data |
| gm81 | Game Maker 8.1 Data |
| gmd | Game Maker 4.x Data |
| gmdb | GMap.NET Database |
| gmez | GameMaker Studio Extension |
| gmf | Game Maker 3.x Data |
| gmk | Game Maker 7.x Data |
| gml | GameMaker Studio GML Script |
| gmo | GNU Gettext Machine Object File |
| gmx | GameMaker: Studio Data |
| gmz | GameMaker: Studio Complete Source |
| gnt | Micro Focus COBOL Generated Code |
| go | Go Source Code |
| gobj | Geoworks Object |
| goc | GEOS GOC Source Code |
| gorm | Gorm Interface Resource |
| gox | The Games Factory Extension Object |
