1)   Source Viewer 1
Source Viewer is a php coded web page allowing you to display the html and php source code of files on your server directly in a browser. It's free of charge.

 2)   PageSpy 1.3.8
PageSpy is an invaluable tool for web development & web design, that will help you save precious time writing and debugging web pages. It can also help you understand the structure and function of existing pages on the web.

 3)   Source Code Browser 2.0
Don't you hate those webpages that try to prevent you from viewing their source code or saving images by disabling Right-Click? Now you can view the source of any webpage, as well as save any image from a webpage, using this source browser software!