day 21




the java cup is half full 3: vultures in waiting


The idea of embedding an interpretive language

in an HTML document is clever, even if the pieces

are nothing new. Many people have been doing

similar things. In fact, there are three competing

languages that employ roughly the same concepts

as Java: JavaScript, Telescript, and Tcl/Tk.

[JavaScript is basically Java without the

ability to declare new classes and therefore

make new objects].

These interpretive languages originally competed

for mind share, but since Java has received the

greatest publicity and support, Tcl and

Telescript are laying claim to being

"complementary." Table 1 lists some comparisons.


TABLE 1. Some comparisons among Tcl, Java, and Telescript.
Source: BYTE, Feb. 1996, p. 104.

Tcl Interpreted scripting language for "sewing together" applications A tool for building agents that roam the Internet Developers bind together existing programs into larger systems Additions do not require recompiling basic structure - simplicity Interpreter is free
Java A full-featured interpreted language for augmenting client-side browsers with small applets Enhances browsers by downloading with an HTML document. Discarded after used. Developers add small scripts called applets to HTML document Java requires sophisticated programmers, handling of details Java interpreter license is expensive
Telescript Extensions to existing languages that add process migration (agents), and server-side functionality to client applications Agents interact in a secure network "cloud." e.g., on servers Sophisticated "permit" mechanism controls access to resources Telescript is not for novices - perhaps the most difficult of the 3 to learn and use Proprietary technology of General Magic


Tcl has been shoved aside as an Internet

scripting language or "BASIC of the Internet,"

while Telescript has been touted as a server

language in contrast to Java- the client

language. General Magic sensed that Java had too

much backing to go head-to-head with it, so

General Magic is re-positioning Telescript as an

intelligent agent language for servers. The idea

is to upload Telescript programs from the client

to the server, where Telescript programs called

agents can meet other agents and interact.

General Magic sees Telescript programs as

server applications and middleware that run in

a server "cloud." The cloud may consist of one

or more servers located anywhere in the

Internet. After finishing their work unattended,

Telescript agents return their results to users

sitting in front of their client machines.

Thus, Java is being touted (by its detractors)

as a client-side mechanism for enhancing the

user experience through animation and control of

the GUI. Tcl is a kind of poor computer

scientist's hacker language, and Telescript is

being positioned at the opposite end of the

poverty scale - as a rich computer scientist's

elegant language.

We should also mention that Microsoft is trying

to pull a fast one on all of the above with its

VBScript, a descendant of Visual BASIC, which

will attempt to run everyone else off the

Information Superhighway. But then this is

another story.

Meanwhile, Java has a troubled future. As we

stated on Monday, there are clouds on the Java

horizon, because like the Village Idiot, Java is

way over its head.

the java cup is half full: 1 2 3 4 5



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