| 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 |
| gnl | GNT Analyzer Result Data |
| gnt | Micro Focus COBOL Generated Code |
| go | Go Source Code |
| gobj | Geoworks Object |
| goc | GEOS GOC Source Code |
| goconvey | GoConvey Profile Data |
| goh | GEOS GOC Header |
| gorm | Gorm Interface Resource |
| gox | The Games Factory Extension Object |
| gpc | Genie Backup Manager Plugin |
| gpdsc | KEIL µVision Generator Pack Description |
| gph | Stata Graph File |
| gpi | GNU Pascal Interface. |
| gr | GX Resource Source File |
| gr2 | Granny 3D Document |
| gradle | Android Studio Gradle Properties |
| grc | GX Compiled Resource File |
| grdecl | Eclipse ASCII Grid Data |
| grh | GX Resource Header File |
| grid | Eclipse Grid Data |
| grn | Granny 3D Document |
| groovy | Groovy Script |
| gs | Gofer Source Code |
| gsh | Visual Studio GL Shader Data |
| gshader | Visual Studio GL Shader Data |
| gsoap | gSOAP Settings |
| gss | GAUSS Source Code |