Adobe Flash Player
Steve Jobs also claimed that a large percentage of the video on the Internet is supported on iOS, since many popular video sharing websites such as YouTube have published video content in an HTML5 compatible format, enabling videos to playback in mobile web browsers even without Flash Player.
Vorbis
As originally recommended by HTML 5, these web browsers natively support Vorbis audio (without a plug-in) using the codice_1 element: Mozilla Firefox 3.5 (and later versions), Google Chrome (from version 3.0.182.2), SeaMonkey (from version 2.0). Opera 9.5 experimental video builds released in 2007 and 2008 have only codice_2 support and play back Vorbis audio included in Ogg video files. Opera 10.5 browser has support for Vorbis audio, WAVE PCM audio and Theora video.