In the meantime, many other JVM have choosen GNU Classpath as their library implementation:
The Aegis VM Project is an on-going effort to develop a lightweight,
secure virtual machine for executing Java bytecode. The Aegis VM will
eventually feature a modular bytecode verification architecture that
allows user-defined static verification procedures to be integrated
into the VM's dynamic linking process through pluggable verification
Although GNU Classpath cannot be directly compiled for use with
GCJ at this time, a lot of work has been done to merge GCJ class
library code and GNU Classpath class library code. This has resulted
in a better version of each. The current merge status between the two
A JVM for the .NET platform.
Runs on top of
A JRE implementation for the Amiga Platform.
JamVM is a Java Virtual Machine which conforms to the JVM specification version 2 (blue book). In comparison to most other VM's (free and commercial) it is extremely small, with a stripped executable on PowerPC of only ~100K, and Intel 80K. However, unlike other small VMs (e.g. KVM) it is designed to support the full specification, and includes support for object finalisation, the Java Native Interface (JNI) and the Reflection API.
The Jaos VM is a JVM using GNU Classpath implemented on top of the
This kernel offers many useful features like garbage collected memory
management, dynamic module loading, and object-oriented model. This makes the
implementation of a JVM particularly attractive and simple.
JC is 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.
Jikes RVM uses GNU Classpath for all of its libraries. Instructions for using
Classpath are provided in the Jikes RVM user's guide as of the Jikes RVM
release 2.2.1 (4/7/03). Nightly regression tests are run against the latest
Classpath release and the Classpath CVS head. The results are posted on the
jikesrvm-regression mailing list, which is archived and available on the Jikes
RVM home page.
JNode is a Java New Operating System Design Effort.
The goal is to get an simple to use and install Java operating system for personal use. Any java application should run on it, fast & secure!
This VM also uses a modified version of the GNU Classpath libraries.
Kaffe OpenVM is a complete virtual machine, library framework and
tools for programming in the java language. It has its own
implementation of part of the core libraries, but uses large parts of
the GNU Classpath framework.
This VM is almost always guaranteed to work with GNU Classpath CVS
Information about ORP
can also be found at
. ORP 1.10 does not work with
current GNU Classpath libraries. Information is available in the
mailing list archives.
SableVM is a robust, extremely portable, efficient, and
specifications-compliant Java Virtual Machine that aims to be easy to
maintain and to extend. It features a state-of-the-art, efficient
interpreter engine. Its source code is very accessible and easy to
understand, and has many robustness features that have been the object
of careful design.
CACAO is a research Java Virtual Machine developed at the Vienna
University of Technology. It has a compile-only approach, which means
there is no interpreter at all but a JIT compiler ported to different
architectures, like Alpha, i386, MIPS, PowerPC, and x86_64. The main
aim of CACAO is to keep the JIT compilation time as small as possible
while producing quite fast code.