Elvis is a clone of vi/ex, the standard UNIX editor. Elvis supports nearly all of the vi/ex commands, in both visual mode and ex mode. Elvis adds support for multiple files, multiple windows, a variety of display modes including "hex" and "html", on-line help, WYSIWYG printing, and other miscellaneous extensions.
Java Development Environment for Emacs (JDEE) is an Emacs-based integrated development environment (IDE) for developing Java applications and applets. Features include multiple code browsers, a JPDA-based debugger, method and field completion, template-based and procedure-based code generation, Java source code interpreter, context-sensitive help, and more.
EO is a templates-based, ANSI-C++ compliant evolutionary computation library. It contains classes for any kind of evolutionary computation (specially genetic algorithms) you might come up to. It is component-based, so that if you don't find the class you need in it, it is very easy to subclass existing abstract or concrete class.
EText Reader (ETR) is a program for reading ETexts from Project Gutenberg texts. It allows selection of font, and foreground and background colors, as well as persistant reading position and bookmarking. It supports browsing, searching, and direct downloading of Project Gutenberg ETexts. It features a built-in online dictionary for instant word definitions while reading.
Ettercap is a network sniffer/interceptor/logger for ethernet LANs. It supports active and passive dissection of many protocols (even ciphered ones, like SSH and HTTPS). Data injection in an established connection and filtering on the fly is also possible, keeping the connection synchronized. Many sniffing modes were implemented to give you a powerful and complete sniffing suite. Plugins are supported. It has the ability to check whether you are in a switched LAN or not, and to use OS fingerprints (active or passive) to let you know the geometry of the LAN.
Euphoria is a simple, flexible, easy-to-learn programming language. It lets you quickly and easily develop programs for Windows, Linux, FreeBSD, NetbSD, OpenBSD, and Mac OS X. Although Euphoria provides subscript checking, uninitialized variable checking, and numerous other run-time checks, it is extremely fast and has the ability to compile to transparently compile native executables via C code.