Forefront security is available on a subscription basis. You do not need to purchase a subscription for the entire product. Microsoft allows you to choose which product is right for you. Below is a list of the different Forefront products available for subscription.
· Microsoft Forefront Client Security
· Microsoft Forefront Client Security Management Console
· Microsoft Forefront Security for Exchange Server
· Microsoft Forefront Security for SharePoint
· Microsoft Forefront Server Security Management Console
Microsoft also offers licensing suites. Forefront Security Suite – Includes all of the forefront products and Exchange Hosted Filtering. Enterprise CAL – All Forefront products, plus the ability to utilize your current CAL investment. Exchange Enterprise CAL – Provides Forefront specifically for the needs of an Exchange environment.
More information on licensing can be obtained at: http://www.microsoft.com/forefront/en/us/pricing-licensing.aspx