H2g2

h2g2 is a British-based collaborative online encyclopedia project engaged in the construction of, in its own words, "an unconventional guide to life, the universe, and everything", in the spirit of the fictional publication The Hitchhiker's Guide to the Galaxy from the science fiction comedy series of the same name by Douglas Adams. It was founded by Adams in 1999 and was run by the BBC between 2001 and 2011. It is often compared to Wikipedia but there are differences between the sites.