| gru | FXpansion GURU Preset |
| grv | CART Grove Data |
| grv | Microsoft Office Groove File |
| grv | PTC Creo Mill Grooving Parameter Data |
| grx | Getright Exported List |
| grxml | XML Grammar File |
| gs | GemStone Document |
| gs-bck | Genius Scan Backup Data |
| gs1 | Genecyst Emulator Saved State |
| gs2 | Genecyst Emulator Saved State |
| gs3 | GameStarter File |
| gs3 | Genecyst Emulator Saved State |
| gs4 | Genecyst Emulator Saved State |
| gs5 | Genecyst Emulator Saved State |
| gs6 | Genecyst Emulator Saved State |
| gs7 | Genecyst Emulator Saved State |
| gs8 | Genecyst Emulator Saved State |
| gs9 | Genecyst Emulator Saved State |
| gsb | FME Desktop Grid Shift Data |
| gsdu | GameSave Manager Database Update |
| gse | GeneSys 3 Export File |
| gse | GSE 2.0 Macro Data |
| gsf | GameExchange2 Skeleton Data |
| gsf | GEMPAK Map File |
| gsf | Gwyddion Simple Field File |
| gsf | MODFLOW Grid Specification Data |
| gsf | z-Tree GameSafe Data |
| gsk | GSAK Macro File |
| gslib | Geostatistical Software Library Data |
| gsms | GameSave Manager Settings Backup |
| gsp | Tascam Gigastudio Performance Data |
| gss | Geometer Sketchpad Script |
| gstat | CSD GSTAT Chemical Modeller Input Data |
| gstore | GMailStore Data |
| gsv | Gameshark SP Save File |