cc allows installation on an unlimited number of computers. the only (very minor) limitation with cc is that you can sign-in on, at most, two computers at any one time.
because adobe makes it simple and fast to sign out from computers a and b when using computer c, that limitation is insignificant if you have an internet connection.
pre-cc versions allow installation and activation on, at most, two computers at any one time. so, you can use these on more than two computers, too but deactivating and activating is not as convenient with those older versions (and still requires an internet connection).
if you want to purchase an lr upgrade with platform swap, Products
if you want to purchase a cs program upgrade with platform swap, http://www.adobe.com/products/catalog/cs6._sl_id-contentfilter_sl_catalog_sl_software_sl_c reativesuite6.html
if you want to check cc plans, Creative Cloud pricing and membership plans | Adobe Creative Cloud
Thanks a lot!