Since it's release, the BBC's iPlayer has required Windows XP, Windows Media Player 10+ and Internet Explorer exclusively for the on demand TV. But after a lot of griping and moaning, it seems an online petition signed by over 16,000 UK residents (or 16,000 email addresses with a "UK postcode") has changed the outcome of its future.
The Government set up the BBC Trust to represent the interests of licence fee payers, and to ensure good governance of the BBC. The BBC Trust has responsibility for ensuring that the correct degree of scrutiny is given to all proposals from the BBC Executive for new services (such as the iPlayer) and any significant changes to existing services. To fulfill this duty, the Trust conducted a Public Value Test on the BBC Executive's proposals to launch new on-demand services, including BBC iPlayer. This included a public consultation and a market impact assessment by Ofcom. In the case of the iPlayer, following the consultation, the Trust noted the strong public demand for the service to be available on a variety of operating systems. The BBC Trust made it a condition of approval for the BBC's on-demand services that the iPlayer is available to users of a range of operating systems, and has given a commitment that it will ensure that the BBC meets this demand as soon as possible. They will measure the BBC's progress on this every six months and publish the findings."
In actual English: more operating system support is due to become available in the future, but don't expect it next week.