Usual lines from their website:
Copy is the easiest way to store, protect and share amazing things. It keeps your computers in sync and your files available from anywhere, even on your mobile devices. With Copy, you can also easily share files with anyone publicly or privately. Copy for companies extends the cloud storage and sharing benefits into corporate environments with user and group management and added control of proprietary company data.
From what I can tell the Windows client is written in C++ (GUI with Qt), the free version of the service gives 5GB and since they're starting for a limited time they're offering 5GB extra per person you invite (for both).
Link to their website: https://www.copy.com
My referral link <<removed referral link, not allowed on Neowin>>
Edited by xendrome, 18 May 2013 - 22:01. Reason: Removed Referral Link