YOCTE! is a freeware, open source, text editor. It was written exactly to be modified, so everyone can have his/her personalized text editor. You can read the FAQ here. Quick notes: for DOS, written in C (using DJGPP, and some specific commands particular to it. Easy to port, however, to another DOS compiler).
It's almost bugless! Except by Backspace, which is very buggy, and delete, which doesn't work if the cursor is at the EOL of the last line in the screen, everything works! New keys added include Tab, Ctrl-Pageup, Ctrl-Pagedown, Ctrl-Home, Ctrl-End. In a few days, functions like 'Find', 'Replace', etc will be working.
The file below contains the full source code, documentation, the license file, and a compiled .EXE. Read the license below, and download it! :)
Copyright (c) 1998 Bruno Barberi Gnecco Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish and/or distribute copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. You cannot sell it, although you may include it in a commercial package with the EXPLICIT WRITTEN permission of the authors and copyright holders. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Now, download it! ZIP file - 75kb
Alternative site: download.