A 100 mbps ethernet standard specified to run over four pairs of category 3 utp wires (known as voice grade, hence the "VG"). It is also called 100VG-AnyLAN because it was defined to carry both ethernet and token ring frame types.

100BaseVG was originally proposed by hewlett-packard, ratified by the iso in 1995 and practically extinct by 1998.

100BaseVG started in the IEEE 802.3u committee as fast ethernet. One faction wanted to keep csma/cd in order to keep it pure Ethernet, even though the collision domain problem limited the distances to one tenth that of 10baset. Another faction wanted to change to a polling architecture from the hub (they called it "demand priority") in order to maintain the 10baseT distances, and also to make it a deterministic protocol. The CSMA/CD crowd said, "This is 802.3 -- the Ethernet committee. If you guys want to make a different protocol, form your own committee". The IEEE 802.12 committee was thus formed and standardized 100BaseVG. The rest is history.