Go to the UNESCO webpage describing the evolution of languages on the Internet since 1996.
Go to the Global Reach website for more information.
According to data published by UNESCO, about one-third of all users of the Internet speak English, but more than two-thirds of the content on the Internet is in English.
(Click on the pie chart to expand the size.)
UNESCO has published a collection of papers by John Paolillo, Daniel Pimienta, Daniel Prado, and others titled Measuring Linguistic Diversity on the Internet.
Read an article about the languages of the Internet (in Spanish) on ElMundo.Es