The BBC has been given the go-ahead to launch a web-based on-demand TV service.

Under the proposals, viewers will be able to watch shows online or download them to their computer for viewing — and Mac users have a chance to lobby the BBC to prioritise Mac support.

The BBC Trust — which replaced the former BBC board of governors last month — gave provisional approval to the online plans, but did demand some changes after consultations with media regulator, Ofcom.

Chair of the BBC Trust, Diane Coyle, said: "Our view is that the BBC's new on-demand services are likely to deliver significant public value, and should be allowed to proceed, but subject to certain conditions in order to reduce the potential negative market impact."

The BBC Trust is demanding the BBC eventually offer its content to end users regardless of computer platform, though no time-frame has been agreed for this.

The Trust explains: "As proposed, the TV catch-up service on the internet relies on Microsoft technology for the digital rights management (DRM) framework. The Trust will require the BBC Executive to adopt a platform-agnostic approach within a reasonable timeframe. This requires the BBC to develop an alternative DRM framework to enable users of other technology, for example, Apple and Linux, to access the on-demand services."

The BBC Trust has launched an online poll, asking users to answer questions such as: "How important is it that the proposed seven-day catch-up service over the internet is available to consumers who are not using Microsoft software?"

The poll takes five minutes to complete and could make the difference as to when Mac support will be introduced at the BBC.

The Trust will reach its final decision before 2 May 2007, after taking account of the responses it receives during the consultation period.

The BBC’s on-demand proposals include four services:
- Seven-day TV catch-up over the internet
- Seven-day TV catch up over cable
- Simulcast TV over the internet (streaming of live television networks)
- Non-digital rights management audio downloads over the internet (podcasting)

The three internet-based services are intended to be offered as part of the BBC iPlayer, which will pull together all the audio and video services offered on bbc.co.uk. Shows are likely to be available for retrospective viewing for up to 30 days.

A policy for syndicating the corporation's on-demand content to operators such as Google, Yahoo or Apple will be drawn up by the Trust.