Open Source Text Editors

Notepad++ Notepad++ is a lightweight text editor that has code coloring and code folding.
Notepad2 Another very lightweight text editor that can be used as a replacement to Windows Notepad.
Cream Not for the feint of heart, this is a modern configuration of Vim. Very powerful but with a learning curve.
Firebug Firebug is a powerful plugin for Firefox that allows you to edit CSS/HTML/Javascript live while you browse the page.