HotSpot VM is the most widely used Java virtual machine today. Initially, it was not developed by Sun Microsystems but originated from a small company called Longview Technologies, and its design was based on the Strongtalk VM, whose technology in turn stemmed from a virtual machine for the Self programming language. Sun Microsystems acquired Longview Technologies in 1997, thereby obtaining the HotSpot VM.
HotSpot VM combines the advantages of Sun’s previous commercial virtual machines with its own innovations, such as the HotSpot feature which refers to its ability to detect hot code segments—frequently executed parts of the program—and prioritize their compilation to enhance performance. In 2006, as part of the effort to open-source Java, the source code of HotSpot VM was released under the GPL license, becoming a key component of the OpenJDK project.
When Oracle Corporation acquired BEA Systems in 2008 and Sun Microsystems in 2009, it came into possession of two leading Java virtual machines: JRockit and HotSpot. To leverage the strengths of both VMs, Oracle planned to integrate select features of JRockit, such as its garbage collection mechanisms and Mission Control tools, into the HotSpot VM while retaining HotSpot’s JIT compiler and other characteristics. This integration was largely completed around the release of JDK 8.