COCA (Corpus of Contemporary American English)


COHA (Corpus of Historical American English)


Google Books (huge n-grams dataset; has AE and BE)

See also Culturomics


Global Web-Based English


TIME Magazine Corpus


British National Corpus


Strathy Corpus of Canadian English


A collection of English corpora


Corpus Concordance English (Lextutor)


More from wikipedia:


HC Corpora — various langauges, download (not searchable online)


USENET ARCHIVES:

The best way to search Usenet is with ordinary Google search, by adding the term site:groups.google.org and then clicking on “Search tools” to set a date range.



Corpora on Github
— JSONs for programmers