From: michelle@crl.dec.com (Michelle Gillespie)
Subject: THE CONCERT PROJECT - September 9, 1992
Keywords: 
		
		Digital Equipment Corporation
		         Cambridge Research Lab 
			       Seminar
Organization: DEC Cambridge Research Lab
Date: Thu, 27 Aug 1992 20:30:33 GMT

                        
		   	 THE CONCERT PROJECT
				
			  Dr. Shuala Yemini
		  IBM - T.J. Watson Research Center


			Wednesday, September 9, 1992
			    3:00 pm - 4:00 pm,
	        Refreshments available starting at 2:30 pm



Abstract:

Computing  increasingly  involves  networks of heterogeneous computers
rather than a single computer.  This arises as often from interconnecting
existing systems as from creating entirely new ones.  Thus, many formerly
autonomous applications and subsystems are being integrated into distri-
buted systems.

Any  of  several languages for distributed programming could be used to
program  such systems if a single  language  were used  consistently.
However,  existing applications are not written in these languages and
most programmers do not know them. "Add-on" RPC  packages such as SUN/ONC,
NCS, or OSF/DCE permit existing application code and programmer skills,
primarily in C, to be partially reused.  However,such packages operate
at a such a low level and expose so many runtime functions that they do
little to hide complexity.  Since details of the architecture show through,
switching from one RPC package to another requires significant recoding.

In this talk we describe our approach of making evolutionary changes to 
existing languages such as C, C++, Fortran, etc., in addition to designing 
a new distributed language, Hermes.  All Concert languages share a common 
distributed programming model that supports dynamic process creation, 
connection, and communication and a common language-independent type 
system.  Language translators and run-time environments, rather than 
programmers, deal with the low-level details of particular operating 
systems and distribution protocols, and with mapping between language-
specific and language-independent types.   Programs in Concert languages 
can thus interoperate both with programs in  different  Concert languages
on different systems, and  with programs written using existing "add-on" 
RPC packages.  The Concert run-time is portable to an open-ended set of 
operating systems and  protocols.

The talk will present the Concert project, and illustrate two Concert 
languages.  Hermes is a new, secure, representation-independent language, 
available for experimental use.  Concert/C is a small extension to ANSI 
C which is in the final stages of implementation, along with the common 
run-time which will eventually support all Concert languages, including 
Hermes.


Speakers Biography:

Saula Alexander Yemini has a BSc in Math and Physics and an MSc in Applied
Math from the Hebrew University in Jerusalem.  She has a PhD in Computer
Science from UCLA, where she worked on language design for and formal 
semantics of Exception Handling.

During 1981/82 she was an assistant professor at NYU.  In 1982, she joined
IBM at the T.J. Watson Research Center.  At Watson she has worked on NIL 
and its follow-on Hermes, both very high level languages for distributed
systems; on Optimistic Recovery, a transparent technique for recovering 
a consistent distributed system state following a failure; and on Concert,
a distributed computing model integrated into conventional languages on 
conventional systems through a minimal set of language extensions.  Dr. 
Yemini is currently the manager of the Distributed Systems Software 
Technology Group at Watson.

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Digital Equipment Corporations Research Lab is located on the north
side of Technology Square, at the junction of Hampshire Street and 
Broadway.  The address is:

     		Digital Equipment Corporation
     		Cambridge Research Lab
     		One Kendall Square, 
		Bldg. 700 - 2nd Floor
     		Cambridge, MA 02139

For questions regarding the seminar, directions, or parking, or to add 
your name to the mailing list, call Michelle Gillespie at 617-621-6601
or send email to michelle@crl.dec.com