| gbsdat | gBilling Server Data |
| gbts | eXtendable Wad Editor GBTS Data |
| gbv | GearBunny Data |
| gbw | Gerbview Workspace Data |
| gbx | Gerber PCB Data |
| gbx | Great Budget Budget Data |
| gbz | Prizoop Compressed ROM Image |
| gc | GraphClick File |
| gc | Sierra Print Artist Greeting Card |
| gc2 | GENECLUSTER GC2 Output File |
| gc3 | GENECLUSTER GC3 Stage File |
| gcat | GUI Design Studio Catalogue File |
| gcb | Google Chrome Backup Archive |
| gcc | Gene Construction Kit Data |
| gccv | Adobe PageMaker GCCV Filter Data |
| gcd | Garmin Nuvi Software Update |
| gcd | General CADD Drawing |
| gcd | Mercury Refcode List Data |
| gcd | Microsoft SharePoint WorkSpace Groove Component Download |
| gcf | GameExchange2 Camera Data |
| gcg | GCG DNA Sequence |
| gci | Gamecube Game Save |
| gck | Gene Construction Kit Data |
| gcm | Gamecube Disk Image |
| gcn | RSView Machine Edition Global Connections Data |
| gco | G-code Code |
| gcod | G-code Code |
| gcode | G-code Code |
| gcp | Spectramap Group Properties |
| gcrd | GnomeCard vCard Data |
| gcs | Gamecube SharkSave Format Data |
| gcs | GameShark SharkSave Data |
| gct | GenePattern Gene Cluster Text |
| gctl | SCCM GIAM Control Data |
| gcw | Microsoft Mathematics Worksheet |
