PET Initiatives in Electronic Collaboration Technologies Expand Opportunities for Users Near and Far September's training in Fortran90 at the CEWES MSRC TEF may become the model for the future of the PET training program. The course was delivered in real time to additional participants at the ARL MSRC and the Ohio Supercomputer Center (OSC) as part of a joint effort involving PET partners OSC, the Northeast Parallel Architectures Center (NPAC) at Syracuse University, and the CEWES MSRC PET Training staff. Using the TANGO Interactive collaboratory tool, developed at NPAC, remote participants were able to attend the training session without leaving their home institutions. Distance education is not a new idea, but these PET efforts are novel because they use newly emergent technologies, including hypertext markup language (HTML-the "language" of the World Wide Web) and Java, to provide a robust teaching environment capable of two-way audio and video, a "whiteboard" that is broadcast to the desktop, and a mechanism for "projecting" viewfoils on each student's computer screen via a shared web browser. The approach used in the Fortran90 training was piloted in another PET collaboration in which Syracuse faculty have delivered semester-long accredited academic classes in computer science to students at Jackson State University (JSU), another PET partner. This project, now in its third semester, may be used to augment the course offerings of the WES Graduate Institute with interactive remote instruction from leading scholars regardless of their location. Several CEWES staff are "attending" this semester's graduate-level class, "Computational Science for Simulation Applications" taught by NPAC's Director, Professor Geoffrey C. Fox, at the CEWES MSRC TEF. Dr. N. Radhakrishnan, director of the Information Technology Laboratory at CEWES, said, "We consider this activity to be of primary importance in achieving our goal of minimizing the 'importance of place' for our Department of Defense research and development community." A secondary benefit of this activity is realized by using JSU as the demonstration partner, thereby extending educational opportunities in high performance computing to a historically black university and utilizing its unique position as the largest producer of African American computer science graduates in the nation. This will allow more minority students to receive education in high technology areas using the Internet. TANGO Interactive, the tool behind these activities, provides the collaborative framework and tools to connect instructors with students. But distance education is merely a special case of the general remote collaboration which the package can facilitate -- replace the students and instructors with the members of a geographically distributed research collaboration who want to hold a short meeting without the time and effort of having to travel, for example. Tango was originally developed under a contract from the Air Force's Rome Laboratory for use in a Command and Control/Emergency Management scenario, which included shared visualization of terrain data extracted from a GIS system. The National Center for Supercomputing Applications (NCSA), another PET partner, is also using Tango to provide the collaborative framework for their Collaborative Data Analysis Toolsuite (CDAT). Tango's flexibility and extensibility have been made possible by its straightforward architecture and reliance on commodity technologies wherever possible. From the collaboration client side, the principle access to the system is through a web browser, which allows the Tango Control Application and other Java applets in the TANGO Interactive package to be loaded on demand. Although many Tango client applications are written in Java, they need not be. Clients have also been written in C, C++, and even Lisp (for a shared Emacs editor). The application program interface (API) for the Tango system is public, and users are encouraged to port existing tools to Tango or develop new ones as their needs require. The Tango Server, also written in Java, manages interactions between client applications. Clients send "events" to the server, which then rebroadcasts them to other clients in that shared session. Apart from a few basic functions, the person who develops the client is free to define shared events which are appropriate to their application. Clients may also communicate directly to each other if the application requires it, as is presently done in the BuenaVista audio/video conferencing module in Tango so as to minimize network latencies. Tango also keeps track of a simple master/slave flag for each instance of a shared application, along with a mechanism to grant and relinquish master status. However once again, the application developer can interpret this flag as appropriate for their particular application, so that a chat tool need not be forced to follow a master/slave model which doesn't make sense, while a whiteboard application can choose to use it to control "passing the pen" among participants. In distance learning applications, instructors typically develop course materials in HTML, either directly or by converting from another format such as a PowerPoint presentation. The courseware is made available through a standard web server, and viewed with a Tango application such as the Shared Browser. Each time the instructor (master) follows a hyperlink, the new URL is sent to all of the student (slave) Shared Browsers. The browsers then use the new URL to load the material from the appropriate web server. The browser already understands what to do with the URL, and Tango doesn't need to be reprogrammed to carry a new type of data every time a new collaborative application is developed. This example also demonstrates how Tango's approach facilitates using commodity tools. The web server hosting the courseware does not have to know anything about Tango, and tools like caching proxy web servers can be used to easily replicate courseware "close" to clusters of students in order to reduce network traffic, since then only URL itself, a short text string, needs to be sent over long-haul networks in real time. September's Fortran90 distance training made use of a Tango Server installed at the CEWES MSRC, which is being readied for roll-out for general use by CEWES MSRC users and their collaborators as well as in future distance training activities, and Tango installations are also planned or under discussion at the other MSRCs. Interested users should look for announcements of this roll-out, as well as for on-site and electronic tutorials on Tango in the near future. Until then, interested users should feel free to try Tango using NPAC's own server, which can be accessed at http://trurl.npac.syr.edu/tango/. With the help of the distance training and education activities, procedures and tools are being developed and refined which will allow remote participation to be the norm rather than the exception in the PET Training program. The Internet itself has already done a great deal to reduce the "importance of place" in work and education. The experience of these PET projects suggests that novel network-based tools, such as TANGO Interactive, have potential that is just beginning to be explored. Note: Visitors to SC98 can learn more about TANGO Interactive and its applications through demonstrations at the High Performance Computing Modernization Office (HPCMO), Center for Research in Parallel Computation (CRPC), and National Computational Science Alliance booths, and in a number of presentations in the Education Program. The Collaborative Data Analysis Toolsuite, which uses Tango, will also be demonstrated at the NCSA booth.