EDT is the text editor from VMS, and earlier from RSX (on PDP-11's). I have been using it all my life (it seems). I am using it right now.
There is a commercial version of EDT out there for PC's, but that wouldn't help me with my OS. I needed an editor, and I detest vi. So I thought I would look at emacs, as people told me it is a good editor, and even rumors of an EDT keypad emulator. Well, emacs that I could find, anyway, was library after library of these macros and this and that and on and on and on up to about 10MB+ of #!@%*. Enough already! I needed something that was self-contained in just one executable and used standard input/output.
And not written in BLISS or LISP!!
So I bit the bullet and wrote most of my version of EDT in about two weeks. It is very much the same as the EDT I used on VMS. Even the wacky 'change mode' commands are intact. The major differences are it removes some of the silly limitations like 255 char record lengths and 24x132 max screen size. The only crt type it works on in screen mode, though, is a VT100. This is what prompted me to add VT100 escape sequence processing to my video and keyboard drivers. Line mode works with 'anything'.
The version I wrote builds and runs on VMS, Linux and OZONE. There is just one module, os.c, that contains conditional code for the three OS's. Anyway, if you want my version, you can download (60k) it (Rev date Nov 14, 2008). It contains three makefiles, one for Linux (makefile), one for OZONE (makefile.ozone) and one for VMS (makefile.vms). The only gotcha is you have to put the help file, edt.hlp in the same directory as the executable.
If you're looking for the keypad DEL W (delete word) function, it is mapped to the Delete key (near the Insert, Home, End keys).
Now there are terminal emulators that run under Linux and other things that say they are VT-100 compatible. The closest thing I could find that actually runs EDT is RXVT. However there was a change I had to make so all keys on the keypad would work. Here is the revised file rxvt-wmr-2.6.3. It turns out PUTTY for WindoesNT emulates well enough to run EDT as does the Linux console.
Don't like what you just did to your file and you want the old one back? The Linux version of EDT simulates VMS and OZONE version numbers by renaming the old file to filename.version~ before overwriting it. It finds an unused number for version.
If your OS crashes while you're editing, or your telnet session dies over a dialup line (or crappy DSL line hear that, what's left of Covad?) no sweat. Just get going again and do edt filename -recover and watch your old edits fly by before your eyes. This is a well-tested 'feature'.
When you start it, it prompts with an *. It is expecting line-mode commands. You can learn them by typing in the help command. Or you can enter screen mode by typing in the c command. Then use the up/down/left/right arrow keys to move around and delete with the delete key. When your file is good, press control-Z and type in command ex (short for exit) and it will write your file out to disk and return back to the shell. If you don't want your changes, use the quit command.
The fancy editing in screen mode is done with the keypad over on the right. The keypad help mode doesn't work, though, I have to fix it.