1. <compiler> A huge volume of spurious error-messages output by a compiler with poor error recovery. Too frequently, one trivial syntax error (such as a missing ")" or "}") throws the parser out of synch so that much of the remaining program text, whether correct or not, is interpreted as garbaged or ill-formed.
2. <messaging> A chain of Usenet followups, each adding some trivial variation or riposte to the text of the previous one, all of which is reproduced in the new message; an include war in which the object is to create a sort of communal graffito.
3. <networking> A collection of interconneced networking devices, typically hubs, that allows those devices to act together as a logical repeater.