Caveman2Cosmos is a CivFanatics community mod that add new features and content to the Civilization 4 experience, with almost daily updates since November 2010. It is the spiritual successor the The Civilization 4 mod Rise of Mankind and its addon A New Dawn, and combined the work of over 100+ modders to create a mod to "rule them all". It is developed by StrategyOnly Productions with its modding team made up of prominent members of CivFanatics.
A very good mod, filled with a lot of content. The new gameplay features are welcome, however, the new units, technologies, wonders, buildings, resources, etc. are in excess. Don't get me wrong, I like a substantial mod, but this makes the game needlessly complicated and slow. I like the idea, and the mod is enjoyable, but I would prefer a version in which it has been cut down, with a few additions to the periods the game accounted for (in terms of technology, maybe twenty), and about thirty or forty technologies in the prehistoric era and futuristic era (in total, preferably leaning towards the future), with maybe fifty new units, about seventy new buildings, thirty wonders, and ten to twenty resources. Of course, the point of this mod seems to be add an excessive amount content, so perhaps this review is somewhat useless, and I should look elsewhere for what I would like. I also think that the art and the descriptions need detail. All in all, a good mod, but it adds too much.