| emx | IBM Rational Software Architect Model |
| epl | TallyMan EPL File |
| erb | Erubis Script |
| erb | Ruby ERB Script |
| erc | Ercato Engine Code |
| erl | Erlang Source Code |
| erlang | Erlang Source Code |
| ers | Altium Designer Assembler Error Messages File |
| erubis | Erubis Script |
| es | ECMAScript Source Code |
| es | Sage CRM Script |
| esav | ANSYS Element Saved Data |
| esk | ESock Module Information |
| esl | Microsoft Visual FoxPro Support Library |
| essl | OpenGL ES Shader Language Data |
| eto | Visual Studio Enterprise Template Object |
| eu | Euphoria Include File |
| ev3b | Lego Mindstorms EV3 Block File |
| ev3m | Lego Mindstorms EV3 for iPad Program |
| ew | Euphoria Include File |
| ewd | IAR System Debugger Data |
| ewo | SIMATIC WinCC External Widget Object |
| ewu | Embedded Wizard Unit |
| eww | IAR System Workspace Data |
| ex | Euphoria Source Code |
| ex2 | ParaView EX2 Mesh Data |
| ex4 | MQL4 Compiled Modules |
| ex5 | MetaTrader 5 Program |
| exml | Tizen Effect Model |
| exob | WeintekHMI EasyBuilder Pro Compiled Project |
| exsd | Eclipse Extension Point Schema |
| ext | Visual Studio .NET DB Project Extended Properties |
| exu | Euphoria Source Code |
| exv | Adobe Extension Script |
| exw | Euphoria Source Code |