British broadcaster BBC has launched an online service that allows people to download television programmes that have been telecast during the previous week, a service similar to that provided in the UK by Channel 4 and ITV, and video-sharing sites such as YouTube.

Called BBC iPlayer, the online service lets viewers download 400 hours of programmes, between 60 and 70 per cent of the total TV output, broadcast the previous week.

However, the service is only available in the UK on computers that run the Microsoft XP operating system, but prevents viewers from making permanent copies on their computers by automatically deleting them after they have been viewed or after 30 days.

All downloaded material is protected by software to prevent copying the material.

Mark Thompson, director general, BBC, says the arrival of the 'on-demand' iPlayer is as important as the first colour television broadcasts in the 1960s.

Ashley Highfield, director of future media and technology, BBC, is quoted as saying that the broadcaster envisons its iPlayer becoming a universal service available not just over the internet, but also on cable and other TV platforms, and eventually on mobiles and smart handheld devices.

At present, it takes half the duration of the programme to download it.