Sets released: Antiquities. Revised Edition, Legends, the Dark,
   Fallen Empires

Major stuff:

   - The types 'poly artifact' and 'mono artifact' were dropped for
   Revised Edition.
   - The tilted-T tap symbol was introduced in Revised Edition.
   - Legends introduced Enchant World, the Legend creature type and
   Legendary lands, as well as gold-bordered cards with more than one
   color.

Trivia:

   - The original 'legend rule' restricted Legend cards to maximum one
   of each name per deck as well as maximum one of any name in play.