The Internet is now used to publish much primary (first disclosed) scientific information, particularly data. Protein sequences, genes, meteorological data, planetary information, and crystallographic data are now routinely deposited and managed on the Web. Top-quality data can be found almost instantly. In many disciplines, it is now a requirement of primary publication that data are electronically available. This has been made possible largely because of Hypertext Markup Language (HTML), which is used to create documents incorporating text, graphics, sound, video, and hyperlinks.