| gal | Corel Multimedia Manager v6 Album |
| gallery | SMART Notebook Gallery |
| galleryitem | SMART Notebook Gallery Item |
| gam | General Game Data File |
| gam | Aureas Theme File |
| gam | Gamma Card Data |
| gaml | GAML Document |
| gap | Generation Analysis and Planning Data |
| gapp | Storyboard Embedded Engine Exported Data |
| gas | Grab-a-Site Data File |
| gasx | GOM Player Data |
| gat | GATTer Configuration Data |
| gb | Nintendo GameBoy ROM Image |
| gb3 | Geekbench 3 Report |
| gb4 | Geekbench 4 Report |
| gba | GrabIt Batch |
| gba | Nintendo GameBoy Advance ROM Image |
| gbaskin | GBA4iOS Game Boy Advance Controller Skin |
| gbb | Wiley eGrade Gradebook Backup |
| gbc | Nintendo GameBoy Color ROM Image |
| gbck | Glary Utilities Backup |
| gbcskin | GBA4iOS Game Boy Color Controller Skin |
| gbd | Garmin Waypoints Data |
| gbe | Gamebook Engine Data |
| gbk | Wiley eGrade Gradebook |
| gbk | GenBank Data |
| gbl | Gerber Bottom Layer Data |
| gbl | Genesis Bitmap Layout |
| gbn | OASIS Montaj Binary Data |
| gbo | Gerber Bottom Overlay Data |
| gbp | Gerber Bottom Paste Mask Data |
| gbp | Genesis Bitmap Pattern |
| gbs | Gerber Bottom Solder Mask Data |
| gbsdat | gBilling Server Data |
| gbv | GearBunny Data |