PTOLEMY II - CiteSeerX

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Introduction
Author: Edward A. Lee
Contributors: The entire Ptolemy team
1.1 Purpose
This document is the first of three volumes describing the Ptolemy II software. This first volume
introduces the software and explains how to use it. The second volume documents the software architecture
and explains how to extend it. The third volume documents the “domains,” which realize models
of computation. Some of these are relatively mature and established, while some are highly
experimental. Indeed, a major part of the Ptolemy Project is experimentation with models of computation.
Ptolemy II is the current software infrastructure of the Ptolemy Project. For the participants in the
Ptolemy Project, Ptolemy II is first and foremost a laboratory for experimenting with design techniques.
It is published freely and in open-source form for several reasons. First, the software complements
more traditional publication media, and serves as a clear, unambiguous, and complete
description of our research results. Second, the open architecture and open source encourages
researchers to build their own methods, leveraging and extending the core infrastructure provided by
the software. This creates a community where much of the dialog is through the software. Third, the
freely available software encourages designers to try out the new design techniques that are introduced
and give feedback to the Ptolemy Project. This helps guide further research. Fourth, the open source
software encourages commercial providers of software tools to commercialize the research results,
which helps to maximize the impact of the work.
The Ptolemy Project is an informal group of researchers at U.C. Berkeley. There have been many
participants in the project over the years (see “Acknowledgements” on page 39 for a list of contributors
to Ptolemy II). Ptolemy II is the third generation of design software to emerge from this group,
with each generation addressing a new set of problems, with new emphasis, and (largely) a new group
of contributors.
Heterogeneous Concurrent Modeling and Design 1