Caesary is a massive multiplayer online city building game set in the post republican era of the Roman Empire, it is a PBBG (Persistent Browser Based Game). As of today (15th May, 2010) Caesary only has one portal on the flash gaming website Kongregate you can play the game now by clicking here. This Wiki will be constantly updated in the coming weeks, so if you can't find the answer to your question check back in future.
UPDATE: You can also play Caesary on the browser gaming portal Aeria Now. Go to Lekool Caesary to play.
OTHER UPDATE: You can play Caesary on Mochi Games. Not anymore