[gkefalas]

You have. For example: http://www.icab.de/mobile.html

Maybe this was a restriction in the past, I'm not sure, but I've been happily running iCab Mobile for quite some time and enjoying it's more grown-up featureset.

[trotsky]

Note that that browser apparently uses Safari/Webkit objects to display content and interpret javascript. So you're still effectively using the iOS safari browser, albeit framed and with a different UI and some management features.

http://www.icab-mobile.de/faq.html

Each Tab is creating a WebKit object, which eats up additional memory.

Here is what someone from Mozilla said rather recently:

http://techcrunch.com/2010/12/27/firefox-iphone-2/

First, he gave the obvious and fairly well-known official answer, “We have no plans to release the full Firefox browser for Apple iOS devices,” Brubeck wrote. Why? Because the current iOS SDK agreement forbids apps like Firefox from including their own compilers and interpreters, Brubeck explains.

But he continues on to note that there are a couple of ways to work within Apple’s system, notably what Skyfire is doing (using Apple’s own build-in WebKit libraries) or what Opera Mini is doing (using a proxy server to execute their JavaScript). “Mozilla could create a browser that did one of those things, but it wouldn’t be related to Firefox in any way,” Brubeck explains.