That is known, but the point is that IE stopped. That has been reported somewhere, can't find a useful link right now but I remember the discussions. It was reported - and what was observable matched the description - that as soon as Netscape was out Microsoft stopped pretty much all their efforts, and IE became the laggard that due to its market share prevented innovation and became a huge obstacle for quite a long time, until loss of market share and the rise of the web app forced their hand.