This is a plug and play external hard drive for my Macbook Pro running OSX, Mountain Lion.  It doesn't require an external power source which makes this the perfect companion for the business traveler, mobile office professional, videographer or photographer.Startup was fast and my laptop recognized it immediately.  The unit is sleek and compact making it great for transport in a backpack or "Man-Purse".  The hard drive runs quietly and there is not a lot of heat emanating from the housing.I do not use or have the need for software to run this hard drive.It's a great unit.  Two thumbs up. 

Question: What is perfect for this unit?
Answer: OSX