| gpp | Guitar Practiced Perfectly 2 Data |
| gpr | GenePix Results File |
| gpro | Genealogy Pro Data |
| gprop | gPhotoShow Pro Image Property Data |
| gps | GOM Player Skin |
| gpscan | GrandPerspective Scan Data |
| gpt | Gerber Pad Master Top Data |
| gpudb | GASW GPUDB Database |
| gpw | Graph Paper World File |
| gpx | GPS Exchange Format Data |
| gpz | IBM DB2 Document Manager Document History |
| gqa | BI/Query Admin Data Model |
| gqf | GrafEq Data |
| gqfl | GrafEq Data |
| gql | BI/Query Data Model |
| gqs | GrafEq Data |
| gqsk | GrafEq Data |
| gqt | GQT Index |
| gqu | BI/Query User Data Model |
| gr | PDFgetX3 GR File |
| gr3 | Pathloss Network Data |
| gr4 | Pathloss Network Data |
| gr5 | Pathloss Network Data |
| gr7 | Simatic S7 Graph Data |
| gr96a | GROMOS96 A Chemical Modeller Input Data |
| gr96n | GROMOS96 NM Chemical Modeller Input Data |
| gradients | Corel Painter Gradient Library |
| grads | PINGO GrADS Data |
| gram | CMUSphinx Grammar Data |
| gramps | GRAMPS XML Data |
| graph | Mascopt Graph Data |
| grc | Affymetrix Grid Control File |
| grd | ElmerGrid Mesh Definition File |
| grd | RFM Irregular Spectral Grid |
| grdb | GRAMPS Database |