FactoryTalk Historian was designed primarily for use with other Rockwell/Allen Bradley products. It can however be used with almost any other product as well. Historian is split into two primary parts, the server and the interface. The Rockwell/AB data is called FTLD (Factory Talk Live Data) and it does use the OSIsoft PI System Interface as Matt1 mentioned. You can also connect third party controllers to FTLD through a third party OPC server. You can order an interface for several products other than Rockwell/AB as well. Siemens, ABB, Citech, GE, Honeywell, WonderWare and several other interfaces are available that will communicate directly to FT Historian. Some have limitations so you may want to talk to a good Rockwell rep before you jump in. We use FT Historian but all of our products are FTLD and use the PI Interface. I just know through the setup and initialization process that other options are available. Also keep in mind that how you order Historian determines what you can do with it. Historian is sold by number of data points, but you must determine how these will be used as well. For example, If you are split 50-50 on devices between Rockwell/AB and other manufacturers and you wanted to order a 5,000 point license, you would order a license for 2,500 Rockwell and 2,500 third party points. If you just order 5,000 Rockwell your third party data will not work.