BBC has released iPlayer, its free on-demand Internet TV service:
Viewers can choose from 400 hours of programmes, between 60 and 70 percent of the total TV output, including hit shows such as "EastEnders, "Doctor Who" and "Planet Earth".
It faces competition from similar services provided by Channel 4 and ITV and from increasingly popular video-sharing sites such as YouTube.
The growth of the Internet, mobiles and hard-drive recorders that save hours of programmes, has destroyed the notion of fixed TV schedules delivered through a TV in the corner of the room.
Broadcasters are under pressure to hold on to viewers by letting them watch programmes when and where they want.
"Our vision is for BBC iPlayer to become 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," said the BBC's Ashley Highfield, director of future media and technology.