Quicktime is typically known for its proprietary codecs as of Quicktime 3.0 or later which have been used to deliver audio and video over the Internet. Not known for top-notch streaming quality, the platform since 1999 has more or less been used to deliver progressive-download movies. Such as those found on ign64.ign.com ; the archived IGN Nintendo 64 news website.
Critics would argue that the platform is bloated, although no spyware or malware is distributed. A stand-alone installer is available for those that do not want iTunes, although iTunes is dependent upon the platform. Most of the proprietary codecs have been reverse-engineered, allowing playback in such players as VLC. Recently, Apple has moved away from standards such as Sorenson Video and qDesign music to insist on somewhat of a truly compatible model ; as supposed by the heavily patented MPEG-4 standard.
Quicktime directly competed with Real Network's real audio / video standard, Microsoft Windows Media, and Xiph's Ogg multimedia platform.
2 - Quicktime sucks! It's so bloated! Yeah, if you try playing back high-res AVC on a Northwood...
3 - Major media outlets use Quicktime to fight off the invasion of the rather sucky Windows Media Video format.
4 - Quicktime is nice, but Theora is more useful for video despite its aging video portion..