APC only works with APC hardware.
The software talks to the firmware on the UPS and tells it what to do in case of a power failure.
With that being said,you get a basic version included with the device,but you can get upgraded versions that can shutdown virtual machines,SQL and Exchange databases.
This is done through the use of a software agent on the affected machines.
IE You have one machine cabled to the UPS ,it can then send out shutdown instructions to machines attached on the LAN that have the agent software installed.
As for Intellipower,are they still in business?