For those who browse by this in the modpack forum and who don't realize it yet:
Cavemen to Cosmos is the biggest and most comprehensive community mod for Civ IV. It is built on top of massive mods:
ROM 2- Rise of Mankind, and AND / RAND -Rise of Mankind - A New Dawn, and it also incorporates REVDCM (the ongoing revolutions modpack for those who want it) and BUG.
Hundreds of thousands of posts for C2C alone.
With twice as many graphics (1.2 gb graphic file alone is 2x size all the other mods on civfanatics combined!). It has new terrains, new features as big as any Civ Expansion, and an incredible amount of good ideas. Not only has it a bunch of new technologies, new eras, and new units also, but it also sports more new concepts than Civ V by at least 4 times. They pioneered increasing the resource limit, rewrote the AI, and turn speed, they are even working with another mod to invent multi-maps to represent planets and a galactic map, so they can incorporate the final frontier mod, and build a complete Galactic Era. They have more alternate earth and optional alternate eras such as prehistoric, clockpunk, post-apocalyptic, and galactic (to name a few) , and more science fiction ideas than most any other mod, and are looking for great balance and realism. In Every major version (now v23) they take time to squash bugs and try to balance things out. Heck they added a living world full of animals of many types, and a new events system tying flammability and electricity to buildings. Many features are customizable and optional. And it is as good as it is big. The care shines more than the amount.
You really should try it out. And if you love another mod also, C2C makes for a great community exploring the best of what's out there. It is awesome to play and getting even better. Don't take my word for it, browse the project forum and convince yourself. And the play is becoming as good as it's promise. Trust me that it will deliver; it already is.
What really make's it special is it's mod team and willingness to consider ideas and helping people participate. What is really exciting and tops the cake is the future of this mod, It's potential is staggering, and it already has accomplished so much.
Anyone who loves CIV should seriously try C2C, and hang around the project forum often enough or I promise, you will be missing out. Just look for yourself how many people say they could kick themselves for missing it.
Check out the rapid progress by following the development threads and try it out yourself-
The development forum for Cavemen2Cosmos:
http://forums.civfanatics.com/forumdisplay.php?f=449
You won't regret it!