1. Free and open source implementations
     Active    Inactive   Java operating systems  

2. Proprietary implementations
     Active    Inactive    Lesser-known proprietary Java virtual machines  

3. See also

4. References

5. External links

This article provides non-exhaustive lists of Java SE Java virtual machines (JVMs). It does not include a large number of Java ME vendors. Note that Java EE runs on the standard Java SE JVM but that some vendors specialize in providing a modified JVM optimized for Java EE applications. A large amount of Java development work takes place on Windows, Solaris, Linux and FreeBSD, primarily with the Oracle JVMs. Note the further complication of different 32-bit/64-bit varieties.

The primary reference Java VM implementation is HotSpot, produced by Oracle Corporation.

Free and open source implementations

Active

• AdoptOpenJDK —provides prebuilt OpenJDK binaries of HotSpot and Eclipse OpenJ9.
• Azul Zulu — is an OpenJDK build supported by Azul Systems and is compliant with the Java SE 8, 7, and 6 standards.
• Bck2Brwsr — is a small JVM capable of booting fast and running in 100% of modern browsers including those that have no special support for Java. Last release in April, 2016.
• CACAO — uses GNU Classpath, supports multiple architectures. GPL. 1.6.0 released September 4, 2012.
• Codename One — uses the open source [https://github.com/codenameone/CodenameOne/tree/master/vm ParparVM]
• [https://aws.amazon.com/corretto/ Corretto] — is an OpenJDK build with long-term support by Amazon.
• [https://github.com/alibaba/dragonwell8 Dragonwell] — is a downstream version of OpenJDK and the in-house OpenJDK implementation at Alibaba optimized for online e-commerce, financial, logistics applications.
• DoppioJVM — a JVM written in TypeScript capable of running in a browser.
• Eclipse OpenJ9 — from IBM, for Windows, AIX, Linux (x86, Power, and Z), macOS, MVS, OS/400, Pocket PC, z/OS.
• GraalVM [https://github.com/oracle/graal/releases CE] — an embeddable, polyglot VM from [https://labs.oracle.com/ OracleLabs], written in Java. It uses the Graal compiler for both AOT and JIT compilations, by means of abstract syntax tree and partial evaluation techniques.
• HaikuVM — for Atmel AVRs (Arduino) and other micros using the leJOS runtime.
• HotSpot — the open-source Java VM implementation by Oracle.
• Jamiga — for the Amiga platform. Depends on GNU Classpath. GPL.
• JamVM — developed to be an extremely small virtual machine compared to others. Designed to use GNU Classpath. Supports several architectures. GPL.
• Jelatine JVM.
• Jikes RVM (Jikes Research Virtual Machine) — research project. PPC and IA-32. Supports Apache Harmony and GNU Classpath libraries. Eclipse Public License.
• JVM.go — a JVM written in Go.
• leJOS — Robotics suite, a firmware replacement for Lego Mindstorms programmable bricks, provides a Java programming environment for the Lego Mindstorms RCX and NXT robots.
• Maxine — meta-circular open source research VM from Oracle Labs and the University of Manchester.
• Multi-OS Engine — Java VM for iOS based on ART .
• RopeVM — the Rope Java Virtual Machine implements the Rope model which is a novel thread level speculative execution model called Rushing Object Parallel Environment. This is a research project aimed at exploiting parallelism in traditional object oriented programs.
• [https://sapmachine.io SapMachine] — an OpenJDK release maintained and supported by SAP.
• uJVM — tiny Java Virtual Machine, mostly to use on embedded systems.

Inactive

• AegisVM — inactive since 2004.
• Apache Harmony — supports several architectures and systems. Discontinued November 2011. Apache License 2.0.
• Avian [https://github.com/ReadyTalk/avian] — a small, easily embeddable Java VM and classpath using just-in-time compilation.
• BicaVM — a JVM implementation in JavaScript
• GCJ the GCC Java compiler, that compiles either to bytecode or to native machine code. The product is currently in maintenance mode.
• IKVM.NET — Java for Mono and the Microsoft .NET Framework. Uses OpenJDK. Zlib License.
• [https://web.archive.org/web/20080316045633/http://www.oberon.ethz.ch/jaos/ Jaos] — Java on Active Object System. Uses GNU Classpath as a standard library. Unmaintained, but source and some documentation available at the [https://www.ocp.inf.ethz.ch/svn/ocp/trunk/Reanimator/JAOS/ OCP repository].
• Japhar — Created by the Hungry Programmers. LGPL. Last release was 0.11, released on 19 June 2002.
• Jato VM — uses GNU Classpath. GPL.
• JC — converts class files from byte-code into C. Uses Soot and GNU Classpath. GNU Library or LGPL licenses.
• JESSICA — Java-Enabled Single-System-Image Computing Architecture.
• JOP — hardware implementation of the JVM. GPL 3.
• Juice — JavaME experimental JVM developed to run on the NUXI operating system.
• Jupiter — uses Boehm garbage collector and GNU Classpath. GPL. Unmaintained.
• JwiK — open source Java VM for 8bit micro for wireless applications.
• Kaffe — uses GNU Classpath. GPL. 1.1.9 released on February 26, 2008.
• leDos — real-mode x86 JVM running on DOS. MPL.
• MateVM — an experimental JIT implemented in Haskell. GPL.
• Mika VM — intended for use in embedded devices. Cross-platform. BSD-style licence.
• miniMV — from UABC-Tij for embedded systems and Wireless Sensor network devices{{citation needed|date=December 2011}}.
• Mysaifu (Windows CE/Windows Mobile) — the only open source Java SE-compatible JVM still in development for PocketPC devices. GPL 2.
• NanoVM — developed to run on the Atmel AVR ATmega8 used in the Asuro Robot, can be ported to other AVR-based systems.
• SableVM — first free software JVM to support JVDMI and JDWP. Makes use of GNU Classpath. LGPL. Version 1.13 released on March 30, 2007.
• Squawk virtual machine — a Java ME VM for embedded systems and small devices. Cross-Platform. GPL.
• SuperWaba — Java-like virtual machine for portable devices. GPL. Discontinued, succeeded by TotalCross.
• TakaTuka — for wireless sensor network devices. GPL.
• TinyVM.
• VM02 — a Java-compatible environment for the Apple II series of computers.
• VMKit of LLVM.
• Wonka VM — developed to run on Acunia's ARM-based hardware. Some code drawn from GNU Classpath. BSD-style licence. No longer under active development, superseded by Mika VM.

Java operating systems

Some JVM's are intended to run without an underlying OS.

• JNode (Java New Operating System Design Effort), written 99% in Java (native compiled), provides own JVM and JIT compiler. Based on GNU Classpath.^[1][2]
• JX Java operating system that focuses on a flexible and robust operating system architecture developed as an open source system by the University of Erlangen. GPL. Version 0.1.1 released on October 10, 2007 version 0.2.
• JOS - Another Java operating system. Last version in 2006.^[3]
• JavaOS - Original project from Sun Microsystems

Proprietary implementations

Active

• Azul Zing JVM — a full compliant Java Virtual Machine based on OpenJDK that uses Azul Systems's C4 garbage collector.
• [https://skelmir.com/products CEE-J] — a clean-room implementation of Sun's Java technology, [https://skelmir.com/ Skelmir] is not a licensee of Oracle.
• Excelsior JET — a licensed Java SE implementation with AOT compiler for Windows, OS X, and Linux on Intel x86 and Linux on 32-bit ARM.
• GraalVM EE — a polyglot VM from [https://labs.oracle.com/ OracleLabs], written in Java and designed for different deployment scenarios (OpenJDK, Node.js, MySQL, Oracle Database, or standalone), uses the Graal compiler for both AOT and JIT compilations, by means of abstract syntax tree and partial evaluation techniques.
• Imsys AB — provides their SNAP (Simple Network Application Platform) JVM running on their proprietary IM1000 and IM3000 microprocessors that feature microcode execution of Java byte codes.
• JamaicaVM (aicas) — a hard real-time Java VM for embedded systems.
• JBlend (Aplix) — a Java ME implementation.
• MicroJvm (IS2T - Industrial Smart Software Technology) — a wide range of virtual machines dedicated to embedded systems (including hard real-time constrained systems), ARM7, ARM9, AVR, AVR32, PPC, MIPS.
• OJVM — also known as "JServer", from Oracle Corporation.
• PTC Perc — a real time Java for embedded systems from PTC, Inc. It is a clean-room implementation of Standard Edition Java. PTC is not a licensee of Oracle.
• SAP JVM — based on HotSpot, available for Windows, Linux and macOS.^[4][5]
• Waratek CloudVM for Java — a multitenant JVM that allows per-tenant isolation, metering and resource control.

Inactive

• Hewlett-Packard — Java for HP-UX, OpenVMS, Tru64 and Reliant (Tandem) UNIX platforms.
• Classic JVM — for IBM OS/400 (superseded by J9).
• Apogee — provides embedded Java using IBM J9 and Apache Harmony Class Library for X86, ARM, MIPS, PowerPC running on Linux, LynxOS, WinCE.
• JBed (Esmertec) — an embedded Java with multimedia capabilities.
• Jinitiator — developed by Oracle before they purchased Sun. Designed to improve support for Oracle Forms in web sites.
• JRockit (originally from Appeal Virtual Machines) — acquired by Oracle for Linux, Windows and Solaris.
• Mac OS Runtime for Java (MRJ).
• Microsoft Java Virtual Machine — discontinued in 2001.
• RoboVM — AOT compiler and runtime which targets iOS, Mac OS X and Linux. Largely based on Android's runtime.
• SAPJVM (SAP) — a licensed and modified SUN JVM ported to all supported platforms of SAP NetWeaver, started as Java 5, in the meantime Java 6 compatible (Windows i386, x64, IA-64; Linux x86, IA-64, PowerPC; AIX PowerPC; HP-UX SPARC IA-64; Solaris SPARC x86-64; i5/OS PowerPC).

Lesser-known proprietary Java virtual machines

• Blackdown Java was a licensed port to Linux of the reference SunSoft implementation. It was discontinued in 2007, after OpenJDK became available.
• Sun CVM — CVM originally standing for "Compact Java Virtual Machine".
• Gemstone — modified for Java EE features (application DBMS).
• Golden Code Development —EComStation and OS/2 port of Java RTE and SDK for Java SE v1.4.1_07.
• HP ChaiVM and MicrochaiVM.
• Intent (Tao Group).
• Novell, India.
• NSIcom CrE-ME.
• PreonVM (Virtenio) — a VM for embedded systems and small devices.

See also

• Comparison of Java virtual machines
• Free Java implementations
• Java processor
• Dalvik virtual machine

References

External links

• List of Java virtual machines (JVMs), Java development kits (JDKs), Java runtime environments (JREs)

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