It’s made using the Guardian’s Content API: http://www.guardian.co.uk/open-platform
A strategy almost exactly opposite to The Times.
Alas, this isn't a long term viable strategy to be followed.
http://en.wikipedia.org/wiki/The_Guardian#Ownership for more info.
The Guardian and the BBC actually leave commercial papers in a bit of a tricky situation with regard to digital strategy here in the UK as they can both give their content away free without any regard to the problems of generating income, as they have guaranteed sources (trust money and license payer money).