A legacy peer-to-peer LAN operating system for DOS, Windows and OS/2 from Linktivity, Tucson, AZ (www.linktivity.com). It supports Ethernet, ARCNET and Token Ring adapters as well as its own twisted-pair adapter at 2 Mbps. LANtastic was popular in the DOS world and in mixed DOS and early Windows environments. Although LANtastic may still be purchased, Linktivity has ceased further development of the product.

Originally developed by Artisoft, Inc., the company was acquired by SpartaCom Technologies in 2000, briefly renamed Converging Technologies and acquired soon after by Inter-Tel, parent of Linktivity. See CorStream.