Forum Moderators: phranque
Probably the Digital Outrage one. I've also seen it as a proprietary CMS for a network of sites (sorry, forgotton who it was. Early version of Lycos? Or Yahoo!?).
You can name your pages with almost any extension you like as long as the parser is set in IIS or Apache.
The .do extension is strictly for JavaServer Pages using the struts framework. The .do extension tells the Application Server to find a config file which calls the proper action class to process the form.
Struts is the ultimate "separate content from display" implementation.
Go to www.sun.com or to apache.org to find out more about JSP and Struts.
But probably worth keeping a note of for future reference.