%T CSP: The Best Concurrent\-System Description Language in the World \- Probably! %A Michael Goldsmith %E Ian R. East, David Duce, Mark Green, Jeremy M. R. Martin, Peter H. Welch %B Communicating Process Architectures 2004 %X CSP, Hoare\[rs]s Communicating Sequential Processes, is one of the formalisms that underpins the antecedents of CPA, and this year celebrates its Silver Jubilee. Formal Systems\[rs] own FDR refinement checker is among the most powerful explicit exhaustive finite\-state exploration tools, and is tailored specifically to the CSP semantics. The CSPm ASCII form of CSP, in which FDR scripts are expressed, is the de\-facto standard for CSP tools. Recent work has experimentally extended the notation to include a probabilistic choice construct, and added functionality into FDR to produce models suitable for analysis by the Birmingham University PRISM tool.