>>10
You're baiting me, but I'll answer anyway.
Personal Editor from the original IBM PC.
Yes, I am THAT old.
No, I don't recommend it to you.
The editor is important. Very, very, very important. If you are ever going to make you own customized programming tool, I think it should be your editor. I have used many, and each one had some advantage over the others. The ideal is to write one that has all those advantages. It is worth the time because you use it all the time.
You'll reach a point in your career where you either get promoted to chattery idiot (manager), or you just HAVE to fix the little niggling problems you've been tolerating for years. And that is why so many editors have been written.