| gmo | GNU Gettext Machine Object File |
| gmr | Game Maker Compiled Game |
| 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 |
| gpx | BASIS GPX Data |
| gr | GX Resource Source File |
| gr2 | Granny 3D Document |
| gra | OpenGL Object Graphic |
| gradle | Android Studio Gradle Properties |
| grafsao | Aleph One Shapes Data |
| grc | GX Compiled Resource File |
| grd | GRX Driver |
| grdecl | Eclipse ASCII Grid Data |
| grdef | Geoworks UI Resource Data |
| grf | GraphEdit Filter Graph Data |
| grh | GX Resource Header File |
| grid | Eclipse Grid Data |
| grm | MINOS Data |
| grn | Granny 3D Document |
| groovy | Groovy Script |
| grp | Amazon Lumberyard Group Data |
| gs | Gofer Source Code |
| Google Apps Script |
| Gosu Class Data |
| gsh | Visual Studio GL Shader Data |
| gshader | Visual Studio GL Shader Data |
| gsoap | gSOAP Settings |
| gsp | Gosu Program |
| Groovy Server Page |
| gss | GAUSS Source Code |
| gst | Gosu Template |
| gsx | Gosu Enhancements Data |
| gsy | Green Shoes Package |
| gt | IBM WebSphere sMash Groovy Template |
| guess | Autotools Triplet |
| gui4cli | Gui4Cli Data |
| gum | GAMBIT Universal Model Machine Data |
| gvy | Groovy Script |
| Groovy Server Page |
| gwe | GameWeaver Executable |
| gwf | Benthic Golden Data File |
| gwsp | Axeda Builder Project |
| gxp | Google XML Pages File |
| gxr | GeneXus Report |
| gyd | Xilinx ISE CPLD Guide Data |
| gyp | Chromium GYP Language File |
| gypi | Chromium GYP Language Include |
| h | C Header File |
| Xcode Objective-C Header |
| h-- | Sphinx C-- Language Header File |
| h2 | H2 Database File |
| h32 | Borland C++ 32bit Include File |
| h86 | µVision Intel HEX Data |
| hac | Helma Actions Script |
| hai | NTgraph Nt09b-2b EMX Library |
| hal | HansaWorld Hansa Applications Language File |
| ham | HAM Executable File |
| haml | Haml Source Code |
| handlebars | Handlebars Template |
| has | Haskell Script |
| hash | Crestron SIMPL Autoupdate Hash Data |
| haxe | Haxe Source Code |
| hbb | HAHTsite HAHTtalk Basic Object Data |
| hbs | HAHTsite HAHTtalk Basic Code Page |
| Handlebars Template |
| hbw | HAHTsite Widget Source Code |
| hcf | Compact HAM Library |
