• JamVM now supports class garbage-collection and unloading.
• Bug-fix for field name/type lookup and obfuscated code.
• Added stub for VMClassLoader.defineClassWithTransformers.

JamVM is a new Java Virtual Machine which conforms to the JVM specification, second edition (blue book). In comparison to most other VMs (free and commercial) it is extremely small. However, unlike other small VMs (e.g., KVM) it is designed to support the full specification, and includes support for object finalisation and the Java Native Interface (JNI).

Excelsior JET is a complete solution for acceleration, protection and deployment of your Java™ applications.

Excelsior JET Optimizer converts your application's classes and jars into highly optimized Intel x86 code and creates a native executable for Microsoft® Windows® or Linux platform.

Excelsior JET Runtime is a complete Java Virtual Machine that works with both Java classes and the executables produced by the Optimizer. It implements the Java SE platform, versions 5.0 and 1.4.2.

Excelsior JET Installation Toolkit facilitates rapid creation of complete installation packages for your optimized Java applications. Installation of the JRE on end-user machines is not required.

Kaffe is a clean room implementation of the Java virtual machine, plus the associated class libraries needed to provide a Java runtime environment. The Kaffe virtual machine is free software, licensed under the terms of the GNU General Public License.

ORP, Open Runtime Platform, is an open source research infrastructure for dynamic compilation and memory management. The current implementation supports programs compiled to bytecode and linked with the GNU Classpath libraries.

The IBM Developer Kit, Java™ 2 Technology Edition, is a development kit and runtime environment that contains IBM's just-in-time compiler, enhanced with a unique Mixed Mode Interpreter and a re-engineered Java 2 virtual machine. Like earlier IBM Java 2 Standard Edition versions, the IBM Developer Kit passes Sun's Java compatibility test and provides stability and performance when you deploy your enterprise e-business applications.

joeq is a Java 2 (JDK 1.3 and 1.4) compatible virtual machine. It is unique in that it is entirely implemented in Java, leading to greater reliability, portability, maintainability, and efficiency. It is also language-independent, so code from any supported language can be seamlessly compiled, linked, and executed dynamically.

kissme is Java Virtual Machine (JVM) freely available under the GPL.

It is currently still under development but can run many console java applications. The Kissme JVM has the following properties:

Today, J2EE application servers have become the central environment for developing and deploying mission-critical business applications. These applications have traditionally been deployed on expensive, single vendor RISC hardware platforms—increasing total cost of ownership. Until now, low cost Intel servers were not considered a suitable alternative for J2EE application servers because of the absence of a competitive, high performing Intel-based Java Virtual Machine (JVM).