Vim vs. Notepad++ vs. CodeMirror

Vim is an advanced text editor that seeks to provide the power of the de-facto Unix editor 'Vi', with a more complete feature set. 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 distributed free as charityware.

Notepad++ is a free (as in "free speech" and also as in "free beer") source code editor and Notepad replacement that supports several languages. Running in the MS Windows environment, its use is governed by GPL License.

CodeMirror is a JavaScript component that provides a code editor in the browser. When a mode is available for the language you are coding in, it will color your code, and optionally help with indentation.