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GBBopen is a modern, high-performance, open source blackboard-system development environment that is based on the concepts that were explored and refined in the UMass Generic Blackboard system and the commercial GBB product. GBBopen is not, however, a clone or updated version of either system. The GBBopen Project is applying the knowledge and experience gained with these earlier tools to create a new generation of blackboard-system capabilities and make them freely available to a wide audience.

GBBopen is structured for high-performance and scalability while maintaining flexibility and adaptability to changes in representation, knowledge-source (KS) components, and control strategies. Multi-dimensional abstraction of blackboard components (“space instances”), blackboard objects (“unit instances”), and proximity-based retrieval patterns is used to provide a semantically meaningful separation of blackboard-repository storage mechanisms from KS and control code. This separation allows storage and search strategies and optimizations to change dynamically as well as to be adapted to a broad range of application areas. GBBopen also provides highly efficient and extensible event primitives that form the foundation for fast, yet effective, opportunistic control reasoning.

At the implementation level, GBBopen is designed as a smooth extension of Common Lisp, providing all the advantages of a rich, dynamic, reflective, and extensible programming language to the blackboard-system architects and component writers. These capabilities are crucial in building complex blackboard-based applications where object representations, knowledge sources (KSs), and control mechanisms will change during development and over the operational lifetime of the blackboard application. GBBopen is tightly integrated with CLOS (the Common Lisp Object System) and provides additional blackboard-specific object mechanisms via the Metaobject Protocol.

The open-source licensing of GBBopen provides a number of important benefits:

• A modular, open-source reference implementation of blackboard-system infrastructure that serves as a basis for research and development activities.
• The availability of source code and the right to modify it enables unlimited improvement and enhancement of the software. It also makes it possible to port the code to new hardware and software, to adapt it to changing conditions, and to reach a detailed understanding of how GBBopen works. Source code availability also makes it much easier to isolate and fix bugs.
• The right to redistribute improvements and extensions to the GBBopen source code.
• The right to use the software.
• There is no single entity on which the future of the GBBopen software depends. This is particularly important given the highly specialized nature of blackboard-system software and the lack of multiple implementations.
• GBBopen supports alternative and additional GBBopen modules for use in research and experimentation.