| gad | GeoDict Analytic Data |
| gaf | GameExchange2 Animation |
| gai | Adobe Glyphlet Development Kit Glyphlet |
| gal | Corel Multimedia Manager v6 Album |
| gal | GenePix Array List |
| gallery | SMART Notebook Gallery |
| gallerycollection | SMART Notebook Gallery Collection |
| galleryitem | SMART Notebook Gallery Item |
| gam | Aureas Theme File |
| gam | Gamma Card Data |
| gam | General Game Data File |
| gam | GAMESS Input Data |
| gamin | GAMESS Input Data |
| gaml | GAML Document |
| gamout | GAMESS Output Data |
| gap | Generation Analysis and Planning Data |
| gapp | Storyboard Embedded Engine Exported Data |
| gas | Grab-a-Site Data File |
| gasx | GOM Player Data |
| gat | Concordance Tag Backup Data |
| gat | GATTer Configuration Data |
| gau | Gaussian Input Data |
| gb | Nintendo GameBoy ROM Image |
| gb3 | Geekbench 3 Report |
| gb4 | Geekbench 4 Report |
| gba | Nintendo GameBoy Advance ROM Image |
| gba | GrabIt Batch |
| gbaskin | GBA4iOS Game Boy Advance Controller Skin |
| gbb | Wiley eGrade Gradebook Backup |
| gbc | Nintendo GameBoy Color ROM Image |
