NPAC Activities in Distributed Computing NPAC's work in networked systems has a strong application focus although it involves development of important generic technology. The two major application areas are distance learning and distributed simulation. Our work in each case is with major national consortia. These include the NCSA Computational Science partnership; the CRPC Center for Research in Parallel Computation; and the DoD Modernization Program. We also lead the forum on the use of Java for High Performance Networked Computing, which involves both a standards setting process and a sequence of very successful workshops. Activity in Distance Learning (http://www.webwisdom.org and http://www.npac.syr.edu/Education ) This involves education with this semester, NPAC teaching a regular course remotely at Jackson State University in Mississippi. This uses our novel Tango collaborative environment, which allows simultaneous support of both synchronous (real- time student teacher interactions) and asynchronous learning. This has both audio-video conferencing and digital video server technology integrated in it and can be used for interesting tests of the value of RTP, RSVP or more generally quality of service network technologies. Tango is currently the only full function multi-language collaboration system and is also being applied to Crisis Management -- an area where again integration of networking and applications is very valuable. Our work in training is in support of the DoD Modernization program and involves 3 sites (ARL, ASC and CEWES) and again involves Tango linked to web-linked databases for asynchronous learning. Here we ensure our work conforms to the new DOD and OSTP ADL (Advanced Distance Learning) initiative developing standards for distributed objects used in education. Activity in Distributed Simulation ( http://www.npac.syr.edu/Projects/WebSimulation/ and http://www.npac.syr.edu/users/gcf/HPcc/HPcc.html ) Here our work has several components unified by a common technology approach based on building systems from commodity technologies (Web and CORBA) which gives automatically high functionality but then requires research into achieving high performance with this approach. Highlights of this activity include HPJava which builds high level support into Java for large scale scientific and engineering computation and is based on linking Java to a high performance library built with Darpa support. WebFlow uses a network of integrated Java and CORBA servers to support large scale distributed coarse grain software integration. This is being used both in classic scientific computations with NCSA and in the Forces Modeling activity of the DOD Modernization program at ARL (Aberdeen). With NCSA we are study'ing integration of our approach with Globus at the low level. We believe that our approach is particularly relevant for this proposal as it based on using the commercial approaches of today's modest performance networks and enhancing them to achieve high performance.