Hello, Occam implements CSP, which is very close to CCS, which is generalised and modernised to Pi-Calculus, which is implemented in Pict. Details follow. Check out: http://www.cs.indiana.edu/hyplan/pierce/ftp/pict/Html/Pict.html I assume this is at least interesting to look at for the Occam community. The Occam language is based on CSP. CSP in turn is very comparable to CCS (see the BibTeX reference at the end). (CCS uses "invisible actions" whereas CSP uses two kinds of choice, denoted with a square $\Box$ and a hat $\sqcap$; furthermore, CCS is more of a framework (for different semantics) than CSP (based only on failure trace semantics) is. Pi-Calculus is a more general form of CCS, which is closer to everyday computing pragmatics, by introducing the notion of a `name' as a primary notion. Naming is often (ab)used in daily practice to cause dynamic binding (e.g. messageName -> methodBody, fileName -> contents). I think this extension, or generalisation, is a major leap forward for concurrency theory, and wanted to report to y'all hackers and matho's that Pi-Calculus exists and has been implemented. Have fun with it! Greetings, Rick van Rein, Spiritus flexibilis in corpore flexibile -- Universiteit Twente * INF-3005 * Postbus 217 * 7500 AE Enschede * 053-4894291 ------------ 8< ------------ 8< ------------ 8< ------------ 8< ------------ @techreport { CSPvsCCS, title = "Notes on the methodology of {CCS} and {CSP}", author = "Glabbeek, R.J. van", month = "Aug", year = "1986", institution = "Centre for Mathematics and Computer Science", address = "PO Box 4079, 1009 AB Amsterdam, the Netherlands", notes = "Report CS-R8624" }