• Per processor core -- A license priced according to the number of processor cores in the computer(s) on which the software will run.

• Core points -- This is a points-based license model that assigns different numbers of points according to the type of processors cores on the computers.

• SAP Named User -- SAP defines a number of different user-based license types -- Professional, Limited Professional, Developer, Employee, etc. Different SAP software usage characteristics are defined for each type.

Virtualization adds yet another twist in the quest for license optimization in the data center. Many software publishers are still grappling with licensing strategies for virtualization and have created unique product use rights, making license management more difficult. Moreover, the dynamic nature of virtual environments -- the mobility of VMs and the speed with which they can be created -- further complicates license management.