Open source research infrastructure for dynamic compiling and memory management; supports programs compiled to bytecode and linked with GNU Classpath libraries. [SourceForge, Open Source, Intel]

Java Virtual Machine. Works on many platforms and includes Just-In-Time (JIT) support for most of them. PersonalJava 1.1 compliant (but does not fully support the Java 2 Platform). [Open Source, GPL]

Enabling the integration of pure Java into Microsoft .NET applications. Tools support J2SE or J2EE, allowing .NET code to access J2EE facilities including EJBs, and JNDI. SE (Standard Edition) and EE (Enterprise Edition) versions.

Combines the jJOS kernel and decaf virtual machine. [Open Source]

Contains releases of the Sun JDK version 1.1.8 for the NetBSD/i386 platform. [Freeware]

A Java virtual machine implementation that converts class files into C source files using the Soot Java bytecode analysis framework, compiles them with GCC, and loads them using a built-in ELF object file loader. [Open source, LGPL]

Information on getting Java (Kaffe) to run on Amiga computers.

Introduction to the Java Virtual Machine, links to JVMs for different platforms, and collection of related articles.

Provides free developer kits for creating and testing Java applets and applications on a number of platforms, including AIX and Linux. Also other Java tools. [Freeware]

JIT plugin for the Sun JVM, for Linux and FreeBSD on x86 processors. Includes support for a transparent distributed object system, MetaVM. [Open Source, GPL]