These are the most widely used online corpora, and they are used for many different purposes by teachers and researchers at universities throughout the world. In addition, the corpus data (e.g. full-text, word frequency) has been used by a wide range of companies in many different fields, especially technology and language learning.
The Corpus of Contemporary American English (COCA) is the only large, genre-balanced corpus of American English. COCA is probably the most widely-used corpus of English, and it is related to many other corpora of English that we have created. These corpora were formerly known as the "BYU Corpora", and they offer unparalleled insight into variation in English. The corpus contains more than one billion words of text (25+ million words each year 1990-2019) from eight genres: spoken, fiction, popular magazines, newspapers, academic texts, and (with the update in March 2020): TV and Movies subtitles, blogs, and other web pages.