Actually, it's not a rumor, it's true. Microsoft IE engineers came up with the basic technology for AJAX programming 10 years before the term AJAX programming was invented. It started in 1996. Of course, it was no iPhone. First it was a Java applet, then it was an ActiveX object. Good ideas don't stay proprietary for too long, and the Mozilla and Safari teams had their own implementations by 1999. The term AJAX was first used in 2005, and W3C started standardizing in 2006. The original IE IFrame element is now called XMLHttpRequest, and it is available in fine browsers everywhere.
It's interesting that Microsoft engineers came up with this idea, but never did much with it. They had no idea where the internet was going, or what kind of technologies would prevail, but they did it anyway. I'm not sure if that qualifies as unmarketed idiocy or accidental visionary, or both. Either way, it's a true story of a common technology innovated by Microsoft, which is a rare occurrence indeed.