We address the issue of deriving a semantically equivalent optimistic computation from a pessimistic computation by application-independent transformations. Computations are modeled by program dependence graphs (pdgs). The semantics of a computation is de-ned by a mapping from an initial state to a nal state, and is realized by a graph rewriting system. Semantics-preserving transformations are ...

In this paper, we propose to combine the advantages of semantic wikis and P2P wikis in order to design a peer-to-peer semantic wiki. The main challenge is how to merge wiki pages that embed semantic annotations. Merging algorithms used in P2P wiki systems have been designed for linear text and not for semantic data. In this paper, we evaluate two optimistic replication algorithms to build a P2P...

Overview • The Object Space Approach: object-oriented essentials and decoupled communication. • Example: a distributed time service. • A distributed protoypical implementation of Object Space. • Employing replication and optimistic asynchrony: a more efficient implementation.