| gdb | Genbox Family History Database |
| gdd | Gerber Drill Drawing Data |
| gdi | Sega Dreamcast GDI Image |
| gdiagramstyle | OmniGraffle Diagram Style |
| gdo | Gerber Data Object |
| gdq | SmartWare Quick Graph |
| gdt | Guitar and Drum Trainer Song |
| gdx | GAMS Data Exchange File |
| gdx | Novapoint Triangle Model |
| gdy | Novapoint Triangle Model |
| gdyn | Gimp Dynamics File |
| ge3 | Mastercam Geometry Data |
| ge6 | WinFamily 6 Genealogy Data |
| geb | Dr. Hardware Data File |
| geb | Sybase PowerDesigner Glossary Model Backup |
| gedata | Qlucore Omics Explorer Data File |
| gee | GeeonxCreator Object Data |
| gef | Geotechnical Exchange Format File |
| gen | Linguistic Tree Constructor Generic File |
| geo | Houdini Geometry Data |
| geodb | Cisco GSS GeoIP Database |
| geodb | Hibernate Spatial H2 GeoDB Database |
| geom | CASTEP Geometry Data |
| geom | STAR-CD v3 Solver Ready Geometry Data |
| gep | GeneXproTools Data |
| ges | GESS Data |
| gew | GeeonxCreator Stream Data |
| gexf | Graph Exchange XML Format |
| gff | General Feature Format File |
| gfi | Genigraphics Graphics Link Presentation |
| gfr | FusionSeq Gene Fusion Report |
| gfs | Immersioni Profile |
| gft | GSP Family Tree Data |
| gft | Torque Font Cache |
| gfv | GfsView Data |