Ken Webb 2010-04-01T17:29:56Z
Discrete Event System Specification (DEVS) is "a modular and hierarchical formalism for modeling and analyzing general systems". There are some significant parallels between DEVS and Xholon. DEVS has been the subject of active research since at least 1976. Numerous books and papers have been published, and various software packages are available, many of which can be accessed from the wikipedia page.For example, Prof. Gabriel Wainer at Carleton University has recently published a book on DEVS, Discrete-Event Modeling and Simulation: a practitioner's approach. His website includes the CD++ software, and a large number of sample applications that demonstrate some of what DEVS can do.
Prof. Wainer has written an introductory tutorial on DEVS.
The Arizona Center for Integrative Modeling and Simulation (ACIMS) is another site I have found to be especially useful. The 2000 book Theory of Modeling and Simulation, Second Edition (Zeigler, Praehofer, Kim) is a detailed account of DEVS. It is based on the original 1976 edition by Bernard Zeigler.
The Modelling, Simulation and Design lab (MSDL) at McGill University uses DEVS to explore multi-paradigm modeling and simulation. This includes some of the same paradigms that have been explored in Xholon.