| er | E-Cell 2 Rule Data |
| era | Electronic Remittance Advice Data |
| erdplus | ERDPlus Database Model |
| ere | EagleEyeOS Report |
| erf | Efficient Reminder v2 Data |
| erfw | Efficient Reminder v5 Data |
| erfx | Efficient Reminder v3 Data |
| erg | CompuTrainer Ergometer Test |
| erg | ErgoVU Data |
| ergo | ERGO Format Data |
| ero | eLibrary Reader Object |
| err | Error Log File |
| ersx | Eraser Scheduled Task List |
| es | E-Prime E-Studio 1.x Experiment File |
| es2 | E-Prime E-Studio 2.x Experiment File |
| esb | Es-Builder Book |
| esco | Nokia Lumia Windows Phone Firmware |
| escopy | ES Explorer Temporary File |
| esd | Algor SuperDraw 3 Data |
| esds | VSE/VSAM Entry-sequenced Data Set |
| ese | Millions Email Generator Email List |
| ese2 | EDIUS Seek Information Data |
| esedb | Extensible Storage Engine Database |
| esf | Steganos Password Manager Container File |
| esform | EasySurveyor Form Data |
| esh | Easy Splitter Splitted Data |
| esi | USoft Application Resources Data |
| esig | HTK Entropic Esignal Format Data |
| esk | eSignal Scan Data |
| esk | Longplay Vesa File |