On What Platform Does ACS Run?

ACS has a few different flavors. They include older versions that can be installed on top of an existing Windows server, a dedicated physical appliance can be purchased from Cisco that is installed in a rack at the customer site and has ACS software preinstalled, and the most popular option moving forward is to install the ACS server logically in a VMware environment such as an ESXi server with ACS running as a virtual machine. Regardless of which implementation you choose, the core functionality of having a centralized database of users, along with authorization rules about what users are allowed to do, is the basic premise of ACS.