GNU Emacs / N Λ N O is a set of configuration files for GNU Emacs such as to provide a nice and consistent look and feel as shown below. It is based on design principles I described in the article "On the design of text Editors" [1] that is available on arXiv. The light theme is based on Material colors [2] and the dark theme is based on Nord colors [3].

The philosophy of nano emacs is to stick as much as possible to vanilla emacs without introducing too much dependencies (or none if possible) and to keep it modular enough. The idea is for users to copy the part they are interested in such as to include them in their own configuration.

[1] https://arxiv.org/abs/2008.06030
[2] https://material.io/
[3] https://www.nordtheme.com/

A full and efficient ISO/IEC 13816:2007(E) ISLISP Implementation.
Commercial software, can be used for free for non-commercial use.
An emacs-like editor for DOS and Windows by the same author can be found on
http://christian.jullien.free.fr/emacs/

A user-friendly program for making electronic circuit diagrams in the browser. Circuits can be exported as netlists, PNG and SVG images and in the native format of the editor.

"ma" is a minimalistic clone of the acme[1] editor used in Plan 9, and is written in Tcl/Tk. It has been tested with Tcl/Tk 8.5, mostly
under Linux. "ma" has successfully been run on Mac OS X with XQuartz, but needs a tiling window manager to be used in a satisfactory way.

Written by Paul Cantrell.
Video TECO is licensed under the GNU license.

WaveDrom draws your Timing Diagram or Waveform from simple textual description.
It comes with description language, rendering engine and the editor.
WaveDrom editor works in the browser or can be installed on your system.
Rendering engine can be embeded into any webpage.

Information about the TECO editor.
Found via http://home.windstream.net/engdahl/teco.htm
See also https://almy.us/teco.html, https://github.com/blakemcbride/TECOC and the home page of Dan Murphy, the author of the original TECO at http://www.opost.com/dlm/

On-line editor, compiler and runtime for various languages. Although Fortran is claimed to be supported, I have not been able to run a simple program.

9ne (pronounced "nine") is an online code editor based on Emacs (Copyright 2006 Rob Rohan). 9ne is a recursive acronym and joke, and means "9ne is not Emacs". 9ne's design goal is to provide an all purpose text editor similar to Emacs but web based.
On 2020-12-19, the original link http://robrohan.com/projects/9ne/ points to Rob Rohan's blog, so replaced it by a link to the github repository, which has been updated on 2008-05-06 and archived by the owner. It is now read-only.