Developing peer-to-peer (P2P) applications became increasingly important in software development. Nowadays, a large number of organizations from many different sectors and sizes depend more and more on collaboration between actors to perform their tasks. These P2P applications usually have a recursive behavior that many modeling approaches cannot describe and analyze (e.g., finite-state approaches). In this paper, we present a formal approach that combines component-based development with well-understood methods and techniques from the field of Attribute Grammars and Data-Flow Analysis in order to specify the behavior of P2P applications, and then construct an abstract representation (i.e., Data-Dependency Graph) to perform analyzes on it.

P2Prec is a social-based P2P recommendation system for large-scale content sharing that leverages content-based and social-based recommendation. The main idea is to recommend high quality documents related to query topics and contents held by useful friends (of friends) of the users, by exploiting friendship networks. We have implemented a prototype of P2Prec using the Shared-Data Overlay Network (SON), an open source development platform for P2P networks using web services, JXTA and OSGi. In this paper, we describe the demo of P2Prec's main services (installing P2Prec peers, initializing peers, gossiping topics of interest among friends, key-word querying for contents) using our prototype implemented as an application of SON.

FNC-2 is a new attribute grammar processing system aiming at expressive power, efficiency, ease of use and versatility. Its development at INRIA started in 1986, and a first running prototype is available since early 1989. Its most important features are: efficient exhaustive and incremental visit-sequence-based evaluation of strongly (absolutely) non-circular AGs; extensive space optimizations; a specially-designed AG-description language, with provisions for true modularity; portability and versatility of the generated evaluators; complete environment for application development. This paper briefly describes the design and implementation of FNC-2 and its peripherals. Then preliminary experience with the system is reported.