A client program that is used to read messages from Internet-based discussion groups (the venerable Usenet) or syndication feeds such as RSS and Atom. Some programs provide a search and organization tool for both newsgroups and feeds as well as local e-mail messages, contacts and other files.

The term used to refer to command-line Unix utilities, such as pine, nn, rn and tin, that were used only for Usenet discussion threads. Graphics-based newsreaders were subsequently developed for Windows and Mac, and newsreader functionality was incorporated into Web browsers and e-mail programs as well. See Usenet, newsgroup and syndication format.