| ftx | WinDev HyperFileSQL Full-text Index |
| fw4 | Framework IV File |
| fwx | FoxWeb Script |
| fx | Microsoft DirectX D3D Effect |
| fxa | FaceFX Actor File |
| fxh | XNA Game Studio HLSL Header File |
| fxl | FaceFX Language File |
| fxml | JavaFX Interface Description |
| fxp | Visual FoxPro Compiled Program |
| fxpl | Adobe Flash FXP Library |
| gab | WinDev Skin Template |
| gambas | Gambas V2 Application |
| gar | GridGain Archive |
| gas | Atari Jaguar GPU Assembly Source |
| gb | Basic4GL Source Code |
| gb1 | Game Maker Backup File |
| gb2 | Game Maker Backup File |
| gbas | GLBasic Source Code |
| gbf | BASIS GUIBuilder Control Data |
| gbk | Embarcadero InterBase Database Backup |
| gbl | Visual Basic Global Declaration |
| gc1 | Golden Common Lisp 1.1 Source Code |
| gcda | Gcov Data File |
| gch | Precompiled C Header File |
| gcl | GNU Common Lisp Source Code |
| gcna | Gcov Compiled Output |
| gcno | Gcov Metadata File |
| gcob | TRANSFER Cobol Source Code |
| gcov | GNU GCOV Logfile |
| gcr | GlowCode Profiling Results |
| gd | Godot Engine Source Code |
| gdb | Embarcadero InterBase Database File |
| gdt | Graph Drawing Toolkit Output |
| gek | GECK/Papyrus Script Editor Script |
| gemspec | RubyGems Gem Specification |