GNU Emacs Windows, Linux
GNU Emacs
By GNU Emacs
For Everybody

Emacs is a text editor and more. At its core is an interpreter for Emacs Lisp ('elisp', for short), a dialect of the Lisp programming language with extensions to support text editing.


Notepad++ Windows
By NotePad++
For Everybody

Notepad++ is a free source code editor (and Notepad replacement), which supports several programming languages, running under the MS Windows environment.
This project, based on the Scintilla edit component (a very powerful editor component), written in C++ with pure win32 api and STL (that ensures the higher execution speed and smaller size of the program), is under the GPL License.

For additional information, please refer to: Notepad++: LSU Overview.

Vim Windows, Mac, Linux
By Vim
For Everybody

Vim is a highly configurable text editor built to enable efficient text editing. It is an improved version of the vi editor distributed with most UNIX systems. Vim is often called a "programmer's editor," and so useful for programming that many consider it an entire IDE. It's not just for programmers, though. Vim is perfect for all kinds of text editing, from composing email to editing configuration files.