1. A software source tree packaged for distribution but see kit. 2. A vague term encompassing mailing lists and Usenetnewsgroups (but not BBSfora) any topic-oriented message channel with multiple recipients. 3. An informATion-space domain (usually loosely correlATed with geography) to which propagATion of a Usenet message is restricted a much-underused feATure. [Jargon File]