The second type of reuse is the inclusion of an already deployed and executing agent as part of a new application. This requires new functionality in both the agent language and agent system infrastructure. The MCC InfoSleuth Project is using the Rosette system for development of agents for the World Wide Web. It has been under development at MCC since 1988. With Rosette, the object-oriented programming model and the Actor concurrent execution model are combined to simplify the development of autonomous, distributed agents.
Most scripting languages are sequential languages with some process ideas grafted on.
Rosette, on the other hand, is an inherently concurrent language framework that makes it natural and simple to express actions that are inherently distributed and can be evaluated concurrently. If a set of operations are not explicitly sequentialized in the Rosette language, they will be executed concurrently by the interpreter. These features make it possible to rapidly integrate new facilities into Rosette. Rosette executes as a single process on Unix platforms, with each actor executing as an ultra-lightweight thread within the single Unix process. Rosette uses a form of remote evaluation to cause the execution of a script on a remote computing system.