It's a very nice early unibody. 4GB RAM, 7200RPM HDD. Rest of the specs here: http://www.everymac.com/systems/app...-2.4-aluminum-15-late-2008-unibody-specs.html Question is what should I install on it? Snow Leopard—very old but my favorite OS X. The OS I run on my other, even newer Macs. The one that this machine was practically designed to run. Mavericks—the most polished of lion turds. A middle ground. Could occasionally help me run a few apps Snow Leopard doesn't support. El Capitan—the most current. Undeniably the best at interfacing with newer iOS devices if nothing else. But also an "allegedly" faster version of a 7 year newer OS known for a fact to be a resource pig. And frankly f**king ugly. Any insight?