EGL External Platform interface

https://github.com/NVIDIA/eglexternalplatform

Lightweight library for vector and matrix math

http://eigen.tuxfamily.org/

Free and Open Source distributed fault-tolerant XMPP server

https://www.ejabberd.im/

Full-text search engine for Java

https://www.elastic.co/

Distributed, RESTful search and analytics engine

https://www.elastic.co/

Library for manipulating ELF files and partial implementation of binutils

https://sourceware.org/elfutils/

Functional, meta-programming aware language built on top of Erlang VM

https://elixir-lang.org/

Elvish = Expressive Programming Language + Versatile Interactive Shell

https://elv.sh/

GNU editing macros (No X flavor)

https://www.gnu.org/software/emacs/

GNU editing macros

http://www.gnu.org/software/emacs/

Expect-like tool for pure shell

http://empty.sourceforge.net/

Enhanced Motif WM fork with multi-monitor and utf-8 support

http://fastestcode.org/emwm.html

Collection of helper tools for emwm

http://fastestcode.org/emwm.html

Detect encoding of text files

http://gitorious.org/enca

Encrypted pass-through FUSE filesystem

http://www.arg0.net/encfs

Dictionary/spellchecking framework

http://www.abisource.com/projects/enchant/

Dictionary/spellchecking framework

https://abiword.github.io/enchant/

X.Org Encoding fonts

https://www.x.org/

High-performance, zero maintenance encrypted DNS proxy

https://github.com/jedisct1/encrypted-dns-server

ASCII to PostScript filter

ASCII to PostScript filter

http://www.gnu.org/software/enscript/

ASCII to PostScript filter

http://www.gnu.org/software/enscript/

Runs arbitrary commands when files change

http://entrproject.org/

Shell helper that automatically sets and unsets environment variables

https://github.com/wojas/envy

The Eye Of Gnome image viewer

https://wiki.gnome.org/Apps/EyeOfGnome

Plug-ins for the Eye of GNOME image viewer application

Extremely lightweight and simple web browser for GNOME 3

http://www.gnome.org/projects/epiphany/

Free UNIX software/file packaging program

https://www.msweet.org/epm/

Utilities to manage Japanese EPWING or Electric-Book based CD-ROM

de i18n package for Eric6 IDE

Functional programming language from Ericsson

https://www.erlang.org/

IDNA implementation in pure Erlang

https://github.com/benoitc/erlang-idna

Manual pages for Erlang/OTP

https://www.erlang.org/

Functional programming language from Ericsson

https://www.erlang.org/

Functional programming language from Ericsson

https://www.erlang.org/

Functional programming language from Ericsson

https://www.erlang.org/

Functional programming language from Ericsson

https://www.erlang.org/

Functional programming language from Ericsson

https://www.erlang.org/

Compatibility library for unicode_util from Erlang R20

https://github.com/benoitc/unicode_util_compat

Extensible shell, derived from plan9's rc

http://wryun.github.io/es-shell/

Sound library for enlightenment package

http://www.tux.org/~ricdude/EsounD.html

Software speech synthesizer

https://github.com/espeak-ng/espeak-ng/

X11 terminal emulator based on rxvt/xterm

http://www.eterm.org/

Input event device header files

VTE based, super lightweight terminal emulator

http://www.calno.com/evilvte/

GNOME 3 multi-format document viewer

https://wiki.gnome.org/Apps/Evince

Integrated mail, calendar and address book distributed suite

https://wiki.gnome.org/Apps/Evolution

Data backends for the Evolution integrated mail/PIM suite

https://wiki.gnome.org/Apps/Evolution

Evolution Microsoft Exchange plugin through Exchange Web Services

https://wiki.gnome.org/Apps/Evolution

Modern replacement for ls

https://the.exa.website/