The economics of computing the convergence of computers and
communications, and recent advances in graphical user interfacesplaced a
powerful new class of electronics products into the hands of the
consumer. These pint-sized computers, called personal intelligent
communicators, can help people in all aspects of their life when
communications is required, from sending electronic postcards to friends
and relatives, to providing information such as news reports, stock
market results, traffic information, and restaurant menus, and to
carrying out financial tranactions, such as purchasing theater tickets,
ordering flowers, and buying and selling stock. But communicators, no
matter how clever, cannot deliver these services alone. A new breed of
software is also required. For example, communicating applications could
maintain your stock portfolio by buying and selling stock under
conditions established in advance. Or they could be used to do ongoing
research on a topic of interest by compiling a reading list and
arranging for interlibrary loan while you sleep. They could even order
flowers and make reservations at your favorite restaurant on your
anniversary.
Barriers and Breakthroughs
Today's networks pose a barrier to development of such applications,
however, because they require the applications to distribute themselves
among both the computers that are dedicated to individual users and the
computers shared by users (the servers). Up till now, that barrier has
been insurmountable. It is one thing to install software on your own
computer or to persuade a network administrator to install it on a
departmental server, but no amount of cajoling will get software onto a
public server.
That obstacle has severely stymied the development of communicating
applications. Consider an application that monitors stock market
activity: users would need to place, outside their personal communicator
and inside a public server, the part of the application that monitors
the market. The company operating the public server, however, cannot
reasonably be expected to offer access to its critical, shared resource
to every user who asks. General Magic has developed a software
technology that resolves the dilemma. Telescript fosters the creation of
a new breed of network that is capable of supporting the development of
communicating applications by making the network a platform for
developers. Telescript technology provides the rules of the road for the
information superhighway, which leads to the electronic marketplace.
What Makes Telescript Different?
To understand Telescript, one must first understand how the basic
paradigm behind it differs from the current paradigm for networking.
Today's networking is based on remote procedure calling (RPC). Under
RPC, a client computer linked to a server orchestrates a specific task
through a series of remote procedure calls. Each call from the client
computer requesting that the server perform a task begets a follow-up
response from the server, indicating the result of that request. The
salient characteristic of RPC is that each interaction between client
and server entails two acts of communication: the first asking the
server to carry out a task, and the second informing the client that the
server did indeed do what was asked of it. Telescript takes a different
approach to networking, called remote programming (RP). Under the RP
model, the computer sends a complete message containing both data and
procedures that the receiving computer executes. These messages are
called agents because they act on behalf of the sending computer even
while in the receiving computer. All of the orchestration is done on-
site at the server. The salient characteristic of RP is that client and
server computers can interact independent of the network once the
network has transported an agent between them. Thus, RP does not require
the ongoing communication necessary in the RPC model. By minimizing the
number of communications necessary to accomplish a task, RP can do
things that would be prohibitively expensive using RPC.
The new approach offers a second advantage--one with far-reaching
implications: Because the RP model enables programs to move between
computers, a communicating application statically installed on a client
computer, for example, can dynamically install its server components on
the appropriate server computers. Such mobility is a profound advantage
on a public network whose servers are owned and operated by public
service providers. RP essentially transforms a network into a platform,
like a personal computer.
Going Places
The basic concept behind Telescript technology can be summarized in the
statement, "Agents go to places. "Agents are the programs previously
described that carry with them instructions. These electronic servants
scurry through cyberspace, performing tasks as directed. The Telescript
environment is full of places, which are venues for services and
information of all kinds. Each place represents, in the electronic
world, an individual or organization in the physical world. One place
might be an individual's mailbox, another a library, or the electronic
representation of a merchant such as a travel agency or florist. A
user's agent, for example, might travel from "home"--its owner's
communicator or computer--out into the network, perhaps to a directory
to look up electronic card catalog places; then travel to those places
to find titles of books on a particular subject; and then in turn go to
a library place to request an interlibrary loan of material before
returning home to report its progress.
No Secret Agents
Computer viruses are making headlines in the trade press these days. A
virus is an unseen and unwanted program that insinuates itself into a
computer and does damage there. The typical virus is parasitic,
attaching itself to an existing program and, by means of that program,
avoiding detection.
Programs written in the Telescript language lack the essential
characteristics of a virus: access to the physical resources of their
host computer and invisibility, or anonymity. The implications of
anonymity--and of its antithesis, identification--were taken into
consideration when Telescript was developed. Telescript places and
Telescript agents lack even the vocabulary required to directly examine
or modify the memory, file system, or other physical resources of the
computers on which they execute.
Furthermore, every Telescript place or agent, as already described,
represents an individual or organization in the physical world, from
which its authority derives. A place's or agent's authority, as well as
its identity, are derived from its telename, which distinguishes the
place or agent from others in the marketplace. It's one thing to claim a
particular authority, or identity, and another to actually have it. In
the electronic marketplace, highly reliable cryptographic forms of proof
are demanded.
Passports in Cyberspace
Because agents spend their lives as the electronic version of the jet
set, their authorities and identities are of special concern. An agent
must prove them at various points along the cyberpath. In particular, an
agent's authority and identity must be reestablished whenever the agent
goes from one region of the marketplace to another, a region being a set
of Telescript places all operated by the same individual or
organization. As with international travel, the agent is denied entry
unless its credentials are validated. Every Telescript place or agent
has a permit that limits its capabilities in the electronic marketplace.
Permits help protect the electronic marketplace from malicious or
misprogrammed agents by preventing such agents' unbridled consumption of
resources. Permits also protect the authorities under which agents
operate by providing misprogrammed agents with a safety net. An agent's
permit plays an important role in the electronic marketplace by enabling
the agent's authority to constrain the agent's activities a priori. In
cases when the agent wants to hang around awhile--monitoring the status
of an air flight, for example--the proprietor of the airline place can
manage the population of agents by restricting access based on how long
the agent wants to stay and based on what sort of resources it wants
access to or wants to use during its stay. In most cases, some record of
an agent's visit is stored on the network resource, primarily for
tracking and billing purposes. However, it is possible for an agent to
visit a place and return (provided permits are in order) without leaving
a record that would take up space on a network/server.
The Vision Thing
The vision of the electronic marketplace has the potential to radically
change the way we perform even the most rudimentary functions of our
life. Intelligent agents can perform the buying and selling functions in
the electronic marketplace, but we also need software developers to
create particular kinds of shops and support structures such as
directories, catalogs, order forms, and other commercial accessories.
Key to that effort will be the development of standards for
electronic commerce. But, finally, the success of the vision will depend
on the average consumer, who is only now getting comfortable with
automatic teller machines and voice mail and who still can't program the
family VCR without help from the kids.
(Sidebar)
General Magic's Magic Cap software environment is both a platform for
communication applications and a foundation for personal communicators.
It includes everything people need to use today's most popular modes of
communication: fax, public electronic mail services, and telephones. In
addition, Magic Cap software incorporates General Magic's
Telescriptcommunication technology and the Telescript-based AT&T
PersonaLink Services.
Magic Cap software also contains features for managing personal
information: address cards that automatically get updated as the
sender's information changes, a calendar that issues invitations to
meetings, and a notebook that supports both free-form and structured
notes. Magic Cap's interface represents real-world objects on a screen,
guiding people through its expandable range of capabilities. The desk
scene contains images of such familiar office items as a telephone, a
name card file, a postcard, a mail in-box and out-box, a file cabinet, a
date book, and a notepad. The desk has drawers for stationery, a
calculator, and other items. To send a message, a user simply taps on
the postcard image, and a new "telecard" fills the screen, ready for
addressing.
By touching the word "Hallway" in the top right of the screen, an image
of a hallway with doors appears. The door labeled "Desk" leads back to
the desk scene, and other doors lead to other rooms, such as the
library. Other rooms can be installed off the hallway by loading
additional software applications. Users can step back one more level, to
the "Downtown" scene, where buildings representing various information
and transaction services appear.
The Magic Cap platform offers independent developers an opportunity to
create a new class of communicating applications and services. Its
extensible user interface, object-oriented architecture, built-in
Telescript technology, and powerful communication building blocks enable
creative developers to enhance Magic Cap. More than twenty Magic Cap
developers have announced product and service plans.
Magic Cap software will be available in handheld communicators and as
software running on personal computers. Matsushita, Motorola, Philips,
and Sony--members of the General Magic alliance--are licensees of the
new technology and are building handheld Magic Cap communicators. The
first communicator based on Magic Cap was announced by Motorola in early
March, and Sony is expected to announce its Magic Cap communicator in
the first half of this year, with products becoming available in the
second half of 1994.
Since both the Magic Cap hardware standard and Magic Cap software are
extensible, manufacturers will be able to create a variety of Magic Cap-
based products that incorporate their unique expertise and that
differentiate their products from others on the market. Two-way
communication is built into every Magic Cap communicator. Customers will
have a range of Magic Cap products to choose from--wireless and
wireline, mobile and stationary--all of which will take advantage of the
growing library of products and services developed by independent
vendors and all of which will communicate.
(Sidebar)
A Little History General Magic began as a project within Apple Computer
to investigate the future of computers beyond traditional business and
home use. In early 1990, Apple Chairman and CEO John Sculley determined
that the best way to pursue the vision was to set up an independent
corporation. This led to General Magic's founding in May 1990. In
February 1991, Sony and Motorola joined Apple in becoming investors in
General Magic and licensees of its technology. AT&T joined the alliance
in January 1992, Philips in November 1992, Matsushita in January 1993,
Nippon Telegraph & Telephone in January 1994, and Toshiba and Fujitsu in
March 1994.