This is exactly the reason why Mozilla appears to be steaming up recently: a couple of years the move was made to radically redesign its renderer to keep an eye open on the emerging W3 standards (CSS was still under discussion). The same happened with the Opera and Konqueror engine. Now, open up the Explorer’s “About Box”: Look for the Mosaic hint. See? Since day and night Explorer has been built around Mosaic. Remember Spyglass? If you’re using Explorer, you’re using ‘second-hand’ technology. Where do you start fixing ‘second-hand’ bugs?
I start to wonder if this is the reason why Microsoft is so reluctant of updating their browser: it isn’t possible to support the new standards without redesigning the internal renderer of Explorer. So while Microsoft seems to have won the “browser war”, looking from a developer’s point of view it looks like Mozilla and Konqueror, Safari and Opera are actually the real front runners, practically stealing the show.
It was a similar revelation to me that the two main flavors of IE (forgetting the shortlived Solaris version) used two different and incompatible rendering engines. I thought the Mosaic/Spyglass code was just to bootstrap things and that by version 3 or so, it was gone.
More innovation, it appears.