TextMate

TextMate is a powerful editor for MacOS X that provides a comprehensive set of tools for writing software in any language. It is based on the popular TextMate project, which was originally created as a text editor for MacOS X's Terminal application. TextMate is now used by many software developers as their primary editor.

TextMate includes a well-designed interface, syntax highlighting for a variety of programming languages, code completion, support for macros and commands, and much more. It also integrates with the MacOS X clipboard, so you can easily copy and paste text between TextMate and other applications.