I actually got a TV licence a few months ago to watch a documentary on the iPlayer. So far only used it to watch just that one documentary - very expensive way to watch one program! No. YouTube uses Adobe's Flash player or the HTML5 video technology (depending on which browser the user is using). The former is a proprietary technology developed originally by a company called Macromedia, the latter was developed as an extension to HTML, a license-free technology developed by the W3C (a group that develops internet standards), by the HTML5 working group "WHATWG". The streaming tech for Flash was developed by Adobe, various different technologies are used for HTML5 streaming video none of which as far as I am aware were developed by the BBC. It would be unlikely, these technologies have been developing very quickly in the past 5 years or so.