previous user of QuickTime could continue to use an older version of the central MoviePlayer application for the remaining lifespan of Mac OS to 2002, indeed, since these additional features were limited to MoviePlayer, any other QuickTime-compatible application remained unaffected. QuickTime 3.0 added support for graphics importer components that could read images from GIF, JPEG, TIFF, and other file formats, and video output components which served primarily to export movie data via FireWire. Apple also licensed several third-party technologies for inclusion in QuickTime 3.0, including the Sorenson Video codec for advanced video compression, the QDesign Music codec for substantial audio compression, and the complete Roland Sound Canvas instrument set and GS Format extensions for improved playback of MIDI music files. It also added video effects which programmers could apply in real-time to video tracks. Some of these effects would even respond to mouse clicks by the user, as part of the new movie interaction support (known as wired movies). QuickTime interactive During the development cycle for QuickTime 3.0, part of the engineering team was working on a more advanced version of QuickTime to be known as QuickTime interactive or QTi. Although similar in concept to the wired movies feature released as part of QuickTime 3.0, QuickTime interactive was much more ambitious. It allowed any QuickTime movie to be a fully interactive and programmable container for media. A special track type was added that contained an interpreter for a custom programming language based on 68000 assembly language. This supported a comprehensive user interaction model for mouse and keyboard event handling based in part on the AML language from the Apple Media Tool. The QuickTime interactive movie was to have been the playback format for the next generation of HyperCard authoring tool. Both the QuickTime interactive and the HyperCard 3.0 projects were canceled in order to concentrate engineering resources on streaming support for QuickTime 4.0, and the projects were never released to the public. QuickTime 4.x Apple released QuickTime 4.0 on June 8, 1999 for Mac OS 7.5.5 through 8.6 (later Mac OS 9) and Windows 95, Windows 98, and Windows NT. Three minor updates (versions 4.0.1, 4.0.2, and 4.0.3) followed. It introduced features that most users now consider basic: Graphics exporter components, which could write some of the same formats that the previously introduced importers could read. (GIF support was omitted, possibly because of the LZW patent.) Support for the QDesign