| Word or
Term |
Description or
Explanation |
| Janet |
Joint Academic Network - the network linking UK
academic institutions (Super Janet, allowing higher speed communication and
other extra facilities, is currently being tested) |
| (Hot) JAVA |
an object-orientated programming language
developed by Sun Microsystems, to be used across distributed systems - it
allows executable 'objects' to be sent across the Internet, rather than the
more traditional text - for example, you could have a graph on your screen of
some data - there could be an update to that data, which JAVA would 'transmit'
to your machine, and update the graph, all without any user intervention - it
is rather like hot-links within documents, hence the term 'Hot' often being
applied to it - apparently Java is american slang for coffee, so you will see
lots of mention of hot java and animated icons of steaming cups of coffee if
you visit any of the java pages - more infomation on JAVA can be found at
http://java.sun.com |
| Javascript |
an interpreted, implicitly typed language,
developed by Sun Microsystems - Javascript source code is designed to be
embedded as markup in HTML documents - it should not be confused with Java |
| Jaz Discs / Drive |
a 1Gb capacity drive from Iomega which is
removable and acts just like a very large capacity fast floppy drive |
| JIT compiler |
see Just-in-time compiler |
| JPEG (1) |
Joint Photographic Experts Group - a body set
up in the USA to produce an industry standard for still picture compression and
storage - the theory is that, with an agreed file format, one company's
decompression program can read the files produced by someone else's compression
program |
| JPEG (2) |
Joint Photographics Expert Group - a filetype
which uses lossy techniques to achieve compression developed by the group as a
platform-independent file-type - JPEG is a standard filetype on Acorns fitted
with RISC OS 3.6 and above and is widely used on the internet - it is one of
the two main standards of file format, the other one being GIF - this is due to
the fact that in the UNIX world (on which the Internet is based) and in the
IBM-Compatible world, there is no dominant vector filetype |
| Jughead |
a search system for finding files in gopher
sites, similar to Veronica |
| Just-in-time compiler |
traditionally, execution of a compiled language
proceeds in three phases: (1) the compiler reads the source code; (2) the
compiler constructs the target code; (3) the target code is executed - aJIT
compiler interleaves these three processes on a call-by-need basis - typically,
the source code is read from an external input |
| this is a concept which has come about
following the success of the Java programming language - the philosophy behind
Java is that it is a platform-independent language, capable of being written
and compiled one one platform, with the executable code being run on any other
hardware platform without modification - in order to achieve this, it is
compiled to a pseudo-machine code called "bytecode", which is then interpreted
by a Java Virtual Machine (JVM) - because they are interpreted, albeit at a low
level, Java programs run more slowly than equivalent programs written in, say,
C or C++ - one way around this is for the JVM to compile the bytecode into real
machine code just before it executes it - this is called Just In Time
compilation (because it happens just as it is needed, and not before) |