Mac OS X Server includes a fully compatible Java VM (virtual machine) based on (JDK) Java Development Kit version 1.1.6. The Mac OS X Server Java VM supports applets that are "100 percent Pure Java." Applets (not VM's) must be tested to documented specifications to become certified as "100 percent Pure Java" compliant.
By supporting applets that are "100 percent Pure Java," Mac OS X Server is considered to be "100 percent Pure Java" compatible and compliant.