The a-z of new media: j

Jack in: To log on to a machine or connect to a network and enter a virtual-reality simulation. It is derived from cyberpunk literature where characters literately connected their brains to a computer via electrodes.
Java: A programming language designed for use on the internet. It was designed to enable the programming of applications that work on different computers or servers regardless of their operating system. It can also be used to build a small programme or applet for use as part of a web page. Applets make it possible for a user to interact with the page.
JavaScript: Not to be confused with Java, JavaScript was developed at Netscape and is a lower-level programming language that can add interactivity or functionality to web pages with simple scripting.
Juggling eggs: A hacker's term for keeping a lot of elements in your head while modifying a programme ("Don't bother me now, I'm juggling eggs.")
Jump page: The term used in web design or architecture for the home page that provides a 'jumping off' point for users. It can also refer to a page that temporarily redirects the user when the page's uniform resourse locator (URL) has been changed or a splash page designed to grab the user's attention.
Just-in-time compiler: A just-in-time compiler is a programme that allows Java code to be understood by whichever operating system or platform it is running on. It enables Java code to be platform independent. Just-in-time is also used in economics to refer to new technologically-enabled production processes that allow goods to be produced quickly to match fluctuations in demand.