OU ICE v3 is hosted on all OU servers in the /includes/ouice/3 directory. The core template also calls the OU header and footer. These are located in the /includes/headers-footers directory.
If you want to develop an OU ICE site locally you'll need to mirror the structure below, downloading all the necessary files.
If you're new to OU ICE you might find this quick step by step tutorial useful.