Java based Systems

Because the TAgents System chooses Java as language to build it, this chapter will first describe the already existing Mobile Agent Systems implemented in Java.

Aglets

Aglets [AGLETS] was developed at the IBM Tokyo Research Lab. It is one of the most widespread and used Mobile Agent currently available. The Aglets Workbench is the platform for running Aglets. Aglets is an event-based and very secure Agent System.

Grasshopper

Grasshopper [IKVG] was developed by the German company IKV++. It was one of the first available commercial Mobile Agent platform. It is written in Java 2 and uses extensible the new security possibilities of this new Java version.

Concordia

Concordia [WPW98] is a Mobile Agent developed by the Mitsubishi Electric ITA Laboratory in Waltham, Massachusetts. It mainly addresses security and reliability concerns. It uses a message queuing subsystem for reliable communication.

Sumatra

A Mobile Agent developed by the University of Maryland. The main attribute of Sumatra [RASS97] is that it uses a modified JVM. The JVM was changed to make an object capable to stop and resume execution at any point in the program. With this approach it therefore solves one of the main disadvantages of the Java languages for Mobile Agents with this approach. Unfortunately it runs for that reason only on a operating system with the modified JVM available.

Voyager

Voyager [GGV] is not only a Mobile Agent, but also a framework for mobile objects and distributed computing. It was developed by ObjectSpace and provides beside the support of mobile objects and agents also an ORB (Object Request Broker), and DCOM for Java. It provides messaging and communication for mobile objects. These features made Voyager a very widespread used packages, but in many cases not especially for Mobile Agents.