Abstract
This paper presents DAOS, a model for exploitation of Andand Or-parallelism in logic programs. DAOS assumes a physically distributed memory environment and a logically shared address space. Exploiting both major forms of implicit parallelism should serve a broadest range of applications. Besides, a model that uses a distributed memory environment provides scalability and can be implemented over a computer network. However, distributed implementations of logic programs have to deal with communication overhead and inherent complexity of distributed memory managent. DAOS overcomes those problems through the use of a distributed shared memory layer to provide single-writer, multiple-readers sharing for the main execution stacks combined with explicit message passing for work distribution and management.

Abstract
This paper presents a multithreaded abstract machine for the TyCO process calculus. We argue that process calculi provide a powerful framework to reason about fine grained parallel computations. They allow the construction of formally verifiable systems on which to base high-level programming idioms, combined with efficient compilation schemes into multithreaded architectures.

Abstract
One of the advantages of logic programming is the fact that it offers many sources of implicit parallelism, such as and-parallelism and or-parallelism. Arguably, or-parallel systems, such as Aurora and Muse, have been the most successful parallel logic programming systems so far. Or-parallel systems rely on techniques such as Environment Copying to address the problem that branches being explored in parallel may need to assign different bindings for the same shared variable. Recent research has led to two new binding representation approaches that also support independent and-parallelism: the Sparse Binding Array and the Copy-On-Write binding models. In this paper, we investigate whether these newer models are practical alternatives to copying for or-parallelism. We based our work on YapOr, an or-parallel copying system using the YAP Prolog engine, so that the three alternative systems share schedulers and the underlying engine.

Abstract
This paper discusses the design of Dorpp, an or-parallel Prolog system for distributed memory architectures, The problem of sharing the environment across a set of nodes that do not physically share memory is addressed in a novel manner by designing a Virtual Shared Memory (VSM) scheme to specifically meet the requirements of or-parallelism The aim is to avoid the overheads of a general VSM scheme that would provide a stricter level of memory coherence than is actually required, The paper identifies the requirements for memory coherence in or-parallel Prolog, and describes how they can be met cheaply, Simulation results are presented and analyzed in order to highlight key aspects of the system's run-time behavior.

Abstract
This paper presents a multithreaded abstract machine for the TyCO process calculus. We argue that process calculi provide a powerful framework to reason about fine-grained parallel computations. They allow for the construction of formally verifiable systems on which to base high-level programming idioms, combined with efficient compilation schemes into multithreaded architectures.

Abstract
Mobile agents are the latest software technology to program flexible and efficient distributed applications. Most current systems implement semantics that are hard if not impossible to prove correct. In this paper we present MOB, a scripting language for Internet agents encoded on top of a process calculus and with provably sound semantics.