Apple defined multimedia before it was even a term, with the announcement of QuickTime in May of 1991, and its introduction at the January 1992 MacWorld in San Francisco. QuickTime was an ambitious project. While it was initially derided as a 'jerky postage stamp video', the technology was more than just a cutting edge movie player running on hardware that wasn't quite to the task; it was an architecture for playing anything time related.
QuickTime developed into being essentially an operating system for media. It can package audio, video, instructions, timecodes and other temporal information using a variety of codecs; different codecs offer strengths suitable for the task at hand and the type of media. QuickTime magically handles the translation between codecs, abstracts the differences in hardware, layers together tracks of data and effects and keeps them all in sync. QuickTime also provides a programing environment to control the playback interface and orchestrate interaction between different types of media.
Apple planned their vision for QuickTime to reach beyond the Macintosh. Later that same year, in 1992, Apple announced QuickTime for Windows. Apple delivered QuickTime 2.0 first on the Mac, and then on Windows in 1994. Since QuickTime was an integrated component of the Macintosh System 7 operating system, the Windows version had to include a direct port of a lot of the secret Macintosh toolbox code. Consequently, it largely bypassed Windows to talk directly to the video hardware.
Concerned about Apple's encroachment upon the PC market they intended to control, Microsoft released a competing standard called Video for Windows. But their product couldn't match QuickTime's performance because Windows, as a graphic DOS application, had never been designed to work with media.
The following year, Apple brought a legal suit against San Francisco Canyon, the developer they used to bring QuickTime to Windows. Canyon had resold Apple's intellectual property to Intel, who then provided it to Microsoft for use in Video for Windows. In order to catch up to QuickTime's performance on the PC, the stolen code allowed them to bypass Windows and use QuickTime's architecture instead. Apple later sued Intel and Microsoft directly, and Microsoft was eventually forced to remove some of the offending code.
Stripped of the stolen performance code, Video for Windows became synonymous, like Microsoft Bob and WinCE, with bad software. So Microsoft entirely scrapped the name and started over with a new plan of attack. Today, while Microsoft admits on their website to having released Windows 1.0 and 2.0, and even suggests that customers used them, they carefully make no mention of Video for Windows.
Meanwhile, by 1996 Apple's Mac OS was stagnating and begging for an overhaul or outright replacement. But QuickTime continued to shine. Apple had introduced QuickTime VR for immersive video, a QuickTime Music Architecture and new QuickTime conferencing features, and QuickTime was establishing itself as the clear leader in the content creation and distribution. This positioned the Mac as the place to create content for multimedia CDs and the developing web audience, even while the Mac platform itself lost marketshare.
Part III > Microsoft: We hate your baby, please kill it