Apple's iTunes online music store is much more than a companion to the iPod from Apple, and also much more a media playback program and even more than a front door to Apple's online download service. iTunes is actually a mini-platform that runs inside Windows to allow Apple and other companies to gather much hardware and software and to create media sharing networks. This is accomplished without interacting with Windows or with the Microsoft built-in Windows Media Player. There are many more copies of iTunes installed than had been bundled with Apple's approximately 100 million iPods. At the recent D: All Things Digital conference, for instance, Steve Jobs estimated that more than 300 million iTunes copies have been installed. Many users download and use iTunes to play music and video and also to buy media used on their computers, whether or not they own iPods. Most iTunes installations are on Windows computers, not Macintoshes, which makes Apple one of the largest software developers for Windows. When iTunes is installed on a Windows PC, also installed is Apple software called Bonjour, which runs independently from the built-in Microsoft network software controlled from the Windows Control Panel. A modified version of the iTunes networking ability allows the new Apple TV product to grab all the music and videos from computers in the home and to play them back through the TV set, even if all the computers are Windows machines.