A case study of CES: a distributed collaborative editing system implemented in Argus

Experience implementing CES, a distributed collaborative editing system, is described. CES was written in Argus, a language that was designed to support the construction of reliable distributed programs, and exhibits a number of requirements typical of distributed applications. The authors' experience illustrates numerous areas in which the support provided by Argus for meeting those requirements was quite helpful, but also identifies several areas in which the support provided by Argus was inadequate. Some of the problems arise because of the distinction in Argus (and in other systems) between locally and remotely accessible data and the mechanisms provided for implementing each. Others arise because of limitations of the mechanisms for building user-defined data types. The authors discuss the problems they encountered, including the implications for other systems. They also suggest solutions to the problems, or in some cases further research directed at finding solutions.<>