The Mozart Programming System

The Mozart Programming System combines ongoing research in programming language design and implementation, constraint logic programming, distributed computing, and human-computer interfaces. Mozart implements the Oz language and provides both expressive power and advanced functionality.

Mozart 2

The PLDC Research Group at UCL is proud to announce the first release of Mozart 2. This release contains a completely redesigned 64-bit virtual machine (compatible with 32-bit and 64-bit processors), and adds an extension interface to the virtual machine to allow language extensions defined within Oz. The PLDC Research Group will use Mozart 2 for future programming education and future research in programming language design and implementation.

The first release of Mozart 2 does not provide support for constraints or distributed programming. We plan for successive releases to support constraint programming with an interface to the Gecode system, and to support distributed programming with a peer-to-peer transactional storage and extensions for network-transparent and synchronization-free programming.

Mozart 1.3.2 and 1.4.0

Previous versions of Mozart, in particular Mozart 1.3.2 and Mozart 1.4.0, remain available to download. They will be deprecated when Mozart 2 is released with constraint and distribution support.

Get started

Download a binary release to start using Mozart.

Learn by exploring the documentation.


Source code is open and publicly available.


The mailing lists are the best way to get in touch. There is also an issue tracker for bug reports. Do pop into the #mozart-oz freenode IRC channel for a chat.