That's somewhat revisionist. IE 3-6 when they were released were much more standards compliant than other browsers, particularly Netscape Navigator. (Layer tags, seriously?) IE was the first browser to fully comply with CSS1. The problem was that once IE6 was out they had so far outpaced their competitors (and abused their monopoly position) that there was no more competition, and since Microsoft was not a web company and had no interest in seeing the web advance, they did nothing for years. Of course years later when Firefox and eventually Chrome came out, IE was horribly outdated - and then when MS tried to make up for lost time with IE7 they failed miserably. That was a browser that was not standards compliant at release. IE8 was better, with very good CSS 2.1 compliance, but still fairly horrible DOM compliance and none of the CSS 3 stuff everyone else already had. 9, 10, 11, Edge are all better, but they still suffer from too long of a delay between releases and customers holding on to old versions for too long.