Mozart For Linux

The Mozart Programming System is an advanced development platform for intelligent, distributed applications. The system is the result of a decade of research in programming language design and implementation, constraint-based inference, distributed computing, and human-computer interfaces.

As a result, Mozart is unequaled in expressive power and functionality. Mozart has an interactive incremental development environment and a production-quality implementation for Unix and Windows platforms. Mozart is the fruit of an ongoing research collaboration by the Mozart Consortium.

Mozart is based on the Oz language, which supports declarative programming, object-oriented programming, constraint programming, and concurrency as part of a coherent whole.

For distribution, Mozart provides a true network transparent implementation with support for network awareness, openness, and fault tolerance. Security is upcoming. Mozart is an ideal platform for both general-purpose distributed applications as well as for hard problems requiring sophisticated optimization and inferencing abilities.

We have developed many applications including sophisticated collaborative tools, multi-agent systems, and digital assistants, as well as applications in natural language understanding and knowledge representation, in scheduling and time-tabling, and in placement and configuration.

The Mozart system provides state-of-the-art support in two areas: open distributed computing and constraint-based inference. Mozart implements Oz, a concurrent object-oriented language with dataflow synchronization.

Oz combines concurrent and distributed programming with logical constraint-based inference, making it a unique choice for developing multi-agent systems. Mozart is an ideal platform for both general-purpose distributed applications as well as for hard problems requiring sophisticated optimization and inferencing abilities. We have developed applications in scheduling and time-tabling, in placement and configuration, in natural language and knowledge representation, multi-agent systems and sophisticated collaborative tools.

Here are some key features of "Mozart":

� Oz is a concurrent object-oriented language. In a first approach, Oz can be programmed in a very similar way to other such languages, like Java. With experience gained, programs tend to become simpler, for example, as they use the powerful concepts of dataflow execution and first-class procedures.

� Oz is an eminently concurrent language. The Mozart system implements ultralightweight threads with preemptive fair scheduling. It easily supports applications with many thousands of threads. Dataflow synchronization is achieved transparently through logic variables.

� Unlike most other programming languages which lock you into a single programming paradigm, Oz unifies into one simple and coherent framework the functional, object-oriented, and logic flavors of programming. This is possible due to the very general and powerful underlying paradigm of concurrent constraint programming.

� Oz is a powerful constraint language with logic variables, finite domains, finite sets, rational trees and record constraints. The system is competitive in performance with state-of-the-art commercial solutions, but is much more expressive and flexible, providing first-class computation spaces, programmable search strategies, a GUI for the interactive exploration of search trees, parallel search engines exploiting computer networks, and a programming interface to implement new and efficient constraint systems.

� Oz goes beyond Horn-clauses to provide a unique and flexible approach to logic programming. Oz distinguishes between directed and undirected styles of declarative logic programming. For both, Oz lets you specify a program's logical semantics separately from its resolution strategy. Powerful tools and libraries are provided built on the concepts of first-class computation spaces and determinacy-driven disjunctions. Together with distribution, this makes Mozart an ideal platform for both intelligent multi-agent systems and parallel search.

� The Mozart system is an ideal platform for open distributed computing: it makes the network completely transparent. The illusion of a common store is extended across multiple sites and automatically supported by very efficient protocols. Full control is retained over network communication patterns, permitting very efficient use of network resources. Reliable, fault tolerant applications can easily be developed.

� Mozart provides first-class software component specifications (called functors) and software components (called modules). The module system facilitates application development and deployment. Both component specifications and components can be transparently referenced through URLs, absolute and relative, and loaded by need. Flexible security policies are implemented by module managers.

� With its dynamic component technology, open computing support, and full-featured implementation, Mozart is an ideal platform for serious programming with mobile agents. A computation can create new computations dynamically. Computations can roam the shared Mozart space at will. Each site has full control over what resources it makes available to incoming computations.

� The Mozart system separates the concerns of application functionality, distribution structure, fault tolerance, and openness (application connectivity). The separation is almost perfect for the first two concerns and quite good for the last two. In the context of aspect-oriented programming, this can be seen as a ``vertical'' approach, where a few aspects are treated in depth, versus the ``horizontal'' approach of tools like AspectJ, which provide primitives for handling many aspects.

� Like Java, Oz is `write once, run everywhere' and provides automatic local and distributed garbage collection. The Oz virtual machine is portable and known to run on most flavors of Unix as well as on Windows.

� The Mozart system comes with an object-oriented library that provides a high-level well integrated interface to Tcl/Tk. This is supplemented with QTk, a tool that supports a mixed declarative/procedural approach to user interface design. This needs only a fraction of the code of standard procedural approaches and is particularly well-suited for building context-sensitive interfaces.

� The Mozart system was designed to be easily extended with new native functionality packaged as DLLs. Comprehensive support is provided for the convenient creation of DLLs. Thus, the Mozart system is not only aggressively open, but also an ideal very high-level glue language.