All Wizards, Sorcerers, Clerics and Favored Souls belong to the Casters’ Guild. They are one of the three authorized sources for the magic crystals which are required to cast magic in the Shattered Earth. (The others being the Druids’ Guild and the Bards’ Guild).
The purpose of the Casters’ Guild is to preserve magic, both keeping records of spells, rituals and magical effects in the Shattered Earth, but also trying to recreate lost information. They function as the scientists and University of the city, and are interested in investigating all phenomena in an attempt to better survive.
Several factions are working on Elemental Summoning, although there are those who believe it isn’t possible without access to the Ethereal planes. Others are looking into Astral plans, as well as attempting to determine what happens to souls now that they have nowhere to go. Which is why raise dead and reincarnate are now easier to cast; also: speak with dead is a bit more effective for people who have died after the the shattering.