Diversica is a module for Civilization IV Beyond the Sword which adds additional graphics and some minor gameplay changes (new units, techs and resources).
It includes both Ethnically Diverse Units and Cultural Citystyles. You can consider it an alternative to Varietas Delectat.
Diversica uses the RevolutionDCM mod to ease having separate installable sub-modules on top of the core mod. All optional sub-modules are included in the download and can be selected upon installation.
Why base it on RevolutionDCM / WoC
Thanks go to the creators of the units found at www.civfanatics.com, including Asioasioasio, Bakuel, Bernie14, Chugginator, Danrell, Dutchking, GeneralMatt, Polycrates, Sepamu92, Snafusmith, TheCapo, TheCoyote and Zerver (and everyone else I forgot) and to NeverMind for the XXL Worlds xml and python code.