Java HotSpot Server VM is an add-on performance module for the Java 2 SDK.

The Java HotSpot Server VM employs state-of-the-art technology to offer many performance enhancements, including an adaptive compiler, improved garbage collection, and thread synchronization.

The Java HotSpot Server VM launches an application using a standard interpreter, but then analyzes the code as it runs to detect performance bottlenecks, or 'hot spots'. It compiles those performance-critical portions of the code for a boost in performance, while avoiding unnecessary compilation of seldom-used code (most of the program). The Java HotSpot Server VM also uses the adaptive compiler to decide, on the fly, how best to optimize compiled code with techniques such as in-lining. The runtime analysis performed by the compiler allows it to eliminate guesswork in determining which optimizations yield the largest performance benefit.

The Java HotSpot Server VM automatically reclaims ('garbage collects') objects that are no longer needed. The Java HotSpot Server VM includes a state-of-the-art garbage collector that is faster and more efficient than the garbage collector of the Java 2 SDK's Classic VM. As an option, the new garbage collector can operate in an 'incremental' mode which eliminates virtually all the program-execution pauses that are typical of current garbage collectors.

The Java programming language allows for use of multiple, concurrent paths of program execution (called 'threads'). The Java HotSpot Server VM provides a leaner, faster thread-handling capability that is designed to scale readily for use in large, shared-memory multiprocessor servers.