Khepera Publishing has a Kickstarter campaign going for their first source book for the Atlantis: The Second Age RPG. The Geographica expands on the various peoples living in the world run by the King of Atlantis.
From the campaign:
The Geographica is the first companion book for the role-playing game Atlantis: The Second Age. The Geographica details the people and culture of the antediluvian world once ruled by the kingdom of Atlantis.
Each continent is explained in great detail with colorful comments by the denizens that have lived or adventured there. With lavishly illustrated maps that include major cities, sites of ancient ruins, and plot hooks for the industrious game master, this book becomes an invaluable tool for player and GM alike.