You mean the different (and now, nearly annually changed) file versions? Wikipedia has a listing of them under DWG, IIRC.
There is a organization now called ODA(opendwg.org) that is working on an open source version of the DWG format (which I'm sure Adesk is thrilled about).
Access a broad range of knowledge to help get the most out of your products and services.
Start with some of our most frequented solutions or visit the Installation and Licensing Forum to get help installing your software.
Upgrading to a 2015 product? Make sure to check these out 1st!