If you are interested in writing your own simple editor,
here's a great tutorial. Description:
Quote:
This is an instruction booklet that shows you how to build a text editor in C.
The text editor is antirez’s kilo, with some changes. It’s about 1000 lines of C in a single file with no dependencies, and it implements all the basic features you expect in a minimal editor, as well as syntax highlighting and a search feature.