TextWrangler 2 is the powerful general purpose text editor, and Unix and server administrator's tool.
What is a text editor?

At its most basic, a text editor is a tool for simply editing text. You can use a text editor for a wide variety of tasks from cleaning up data, to editing configuration files on your Mac or server, to writing HTML or coding.

TextWrangler is a...
General Purpose Text Editor
Programmer's Text Editor
Unix And Server Administrator's Tool
Powerful Text Transformer And Manipulator
Good Mac OS Citizen
Powerfully Useful Tool
product developed in the best traditions of Bare Bones Software, with high performance, ease of use, a rich feature set, and the ability to read its own release notes