Apple's iTunes U has hit the 600 million download mark, according to The Loop.

iTunes U was first launched in May 2007 and set out its stall as a dedicated area within the iTunes Store offering free educational material.

Offering resources such as lectures, demonstrations and lessons, iTunes U has come a long way in just over four years, with more than 1,000 educational establishments with active accounts.

According to the report, 30 percent of traffic comes from iOS devices and 60 percent from outside the US. iTunes U is available in 123 countries.

Organisations such as the Tate, Oxford and Cambridge universities and Trinity College Dublin all offer content on iTunes U.

In August 2010, Apple celebrated 300 million downloads from iTunes U, meaning that it has doubled that haul in little over a year.