e3 is a full-screen, user-friendly text editor with an interface similar to that of either WordStar, Emacs, Pico, Nedit, or vi. It's heavily optimized for size and independent of libc or any other libraries, making it useful for mini-Linux distributions and rescue disks. The assembler version supports Linux, FreeBSD, OpenBSD, NetBSD, Win9x, QNX, Atheos, BeOS, ELKS, and DOS. There is also a separately distributed version written in C which supports some other Unix versions and CygWin. It is also possible to use regular expressions by using child processes like sed. e3 has a built in arithmetic calculator.
e93 is a portable window-based text editor oriented to the needs of programmers. It uses the mouse, selections, cut/copy/paste, and closely follows the model of editors on the Macintosh and NeXT platforms. It supports columnar selection by allowing multiple pieces of the text to be selected simultaneously (this is perhaps its most unique feature), imposes no limits on the line length, file length, or number of simultaneous files which it can edit, and has many other features.
Eev.el is a simple Emacs Lisp library that lets you treat portions of a text file as shell commands, chunks of code for programming languages or as hyperlinks; its intention is to let people record into plain ASCII files their interaction with the computer, and to let them edit and play back any block of code in those files easily. The hyperlinks can point to places in manpages, Info pages and text or HTML files, and they are seen as comments by all programming languages; using them you can place pointers to all relevant online sources of information inside the code.
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.