Despite the fact that there are hundreds -- maybe thousands -- of browser brands out there, there are actually only a handful of browser *engines*. Some of the biggest browser engines are Trident (built by Microsoft), Gecko (Mozilla), KHTML, and Opera. Gecko and KHTML are open source applications, while Trident and Opera are privately-held.

To make a web browser, someone would start with a browser engine, and then build customizations on top of it. The Avant browser you're referring to started with Trident (like IE does). I've recommended one called Browzar in the past, which is also based on Trident. There are hundreds of others.

The Gecko engine is the basis of Mozilla Firefox. (There is also a browser called Mozilla.) Netscape primarily used Gecko, although a user could change a setting to force it to use the Trident engine on their Windows computer.

KHTML is the basis of Apple's Safari browser, although when they started buildign Safari they "forked" the engine, which means they never intend to integrate future upgrades of the KHTML engine back into Safari. Apple's forked version of the browser engine is called WebKit.

I'm not aware of any browsers that are based on Opera, because Opera is not open source, and not installed by default in any operating system. It's a commercial product.

I hope this shed a little light on the topic.

By the way, I can recommend another very interesting browser that lets you switch between the Trident and Gecko engines. It's called "Maxthon" (used to be called MyIE2). It is from China, and has an incredible number of little friendly touches. You have to see it to believe it. www.maxthon.com

Thank you so very much for the info! Just downloaded Maxthon, taking it for a test drive. Since I'm a great admirer of Chinese innovation will give this one a good long trial. Thanks again!