Vim. See Vi Lovers Home Page
NEdit is a multi-purpose text editor for the X Window System. (License: GNU GPL)
ne is a free (GPL'd) text editor based on the POSIX standard that runs (we hope) on almost any UN*X machine. ne is easy to use for the beginner, but powerful and fully configurable for the wizard, and most sparing in its resource usage.
jEdit Written in Java, so it runs on Mac OS X, OS/2, Unix, VMS and Windows. (License: GNU GPL v2)
sed.sf.net a collection of sed documentation and scripts.
JOE
GNU nano see also: GitHub - nanorc/nanorc Improved syntax highlighting for GNU nano.
JED is a freely available text editor for Unix, VMS, MSDOS, OS/2, BeOS, QNX, and win9X/NT platforms.
ee An easy to use text editor. Intended to be usable with little or no instruction. Provides a terminal (curses based) interface. Features pop-up menus.
J is a text editor written in Java and distributed under the GNU General Public License.
JuffEd
GNU Moe is a powerful, 8-bit clean, console text editor for ISO-8859 and ASCII character encodings. It has a modeless, user-friendly interface, online help, multiple windows, unlimited undo/redo capability, unlimited line length, global search/replace (on all buffers at once), block operations, automatic indentation, word wrapping, file name completion, directory browser, duplicate removal from prompt histories, delimiter matching, text conversion from/to UTF-8, romanization, etc.