Firefox

Right! The thing I asked him about was if XMLHttpRequest would be natively supported instead of having to use an ActiveX object. His reaction was oh, hmm, that sounds kinda cool but nah. At that time dynamic HTML still wasn't all that old, web pages were still mostly content that just sat there. And now we could eliminate page refreshes and server-side state maintenance, and have little apps run in the browser and interact with APIs. I was super psyched about this changing the whole face of the web, and that MS would lead the way. But sadly by then it had become all about getting people to re-buy Windows every few years.