"On December 13, 2006, a Square Enix representative informed Tokyo reporters that the already announced Final Fantasy XII: Revenant Wings would be joined by other games in a new subseries known as the Ivalice Alliance. Final Fantasy Tactics: The War of the Lions is a PlayStation Portable port of the original Final Fantasy Tactics game. Final Fantasy Tactics A2: Grimoire of the Rift is a Nintendo DS sequel to Final Fantasy Tactics Advance, albeit set in the actual Ivalice world and not an artificial illusory world, unlike its predecessor. Another title in the collection, Final Fantasy XII International Zodiac Job System, was revealed on May 8, 2007.
Executive producer Akitoshi Kawazu explained that the aim of the Ivalice Alliance is to "spread the word about the world of Ivalice", and to bring more players into the franchise, with new titles not restricted to the standard role-playing game genre but also tactical games and games similar to Vagrant Story. Revenant Wings director Motomu Toriyama noted that with the large and original team that worked on Final Fantasy XII, Ivalice became more Square Enix's world than that of the former Quest team, and that the Ivalice Alliance world is thus slightly more influenced by Final Fantasy XII than the earlier Ivalice titles.
Crystal Guardians W1, a mobile phone game related to Final Fantasy Tactics A2 has been revealed by Square Enix. Two additional chapters, titled Crystal Guardians W2 and Crystal Guardians W3, have also been released"
Source: Wikipedia, "Ivalice", available under the CC-BY-SA License.