On the same day as announcing that Opera has 300 million users, we’re also announcing that for all new products Opera will use WebKit as its rendering engine and V8 as its JavaScript engine. It’s built using the open-source Chromium browser as one of its components. Of course, a browser is much more than just a renderer and a JS engine, so this is primarily an “under the hood” change. Consumers will initially notice better site compatibilty, especially with mobile-facing sites – many of which have only been tested in WebKit browsers. The first product will be for Smartphones, which we’ll demonstrate at Mobile World Congress in Barcelona at the end of the month. Opera Desktop and other products will transition later.

In the short term, this will be good for Opera (less time spent on the rendering engine means more time available to work on user-facing features) and perhaps for some web designers, I can’t help but think it’s an overall step in the wrong direction. We’re left with only three major rendering engines—WebKit, Gecko and Microsoft’s proprietary Trident—which will likely mean a further focus on bad designers building sites for WebKit rather than the standard. Just look back to the bad old days of the Netscape/IE browser war…and the horrible, horrible fallout when Netscape was crushed and only Internet Explorer was widely used for the following decade.On the other hand, having the Opera developers’ expertise contributing to the WebKit project can only be good for the other browsers using it.

300 million users and move to WebKit [Opera Developer News]

If Microsoft were to switch from their proprietary “Trident” rendering engine to an open source solution such as WebKit or Mozilla’s Gecko, it would do far more than simply save designers headaches.

It would save Microsoft money and development time, net them some publicity, and vastly improve their web browser? What’s not to like?

What is WebKit? It’s an open source HTML rendering engine that powers Google Chrome, Apple Safari, the iPhone’s MobileSafari, and just about any Mac OS X application that displays web pages.

Internet Explorer could at long last become reasonably standards compliant, and Microsoft would be able to put their resources towards improving their browser’s user interface, rather than wasting time reinventing the wheel.

Maybe it’s just wishful thinking, but there is no reason it couldn’t be done.