A set of Usenet newsgroups containing articles on controversial subjects often considered outside the mainstream. Alt is an abbreviation for alternative.
These newsgroups were originally created to avoid the rigorous process required to create an ordinary newsgroup. Some alt newsgroups contain valuable discussions on subjects ranging from agriculture to wolves, others contains sexually explicit material, and others are just for fun. Not all ISPs and online services give access to the complete set of alt newsgroups.
See also mailing list; moderated newsgroup; newsgroup; unmoderated newsgroup.