JavaGran is a web-based computer program for processing sound. It is so-named because it is programmed in the language Java, which is designed to work within web browsers and on a variety of different computers, and because it uses a technique called 'granulation.' It makes use of JSyn, a kind of special extension to Java which allows for fast computer music stuff, but more about that later...
JavaGran was created for the Alliance for Canadian New Music Projects' Contemporary Showcase 2002 Festival.
In a nutshell, JavaGran allows you to take a sound (either one of the few provided or ones that you record yourself) and time-stretch or shrink it; that is make it last longer or shorter than it did originally. JavaGran lets you layer several sounds at once and process them independently in realtime, allowing the user to perform and improvise. Through a simple interface you can record sounds of up to 5 seconds in length from your computer's microphone or soundinput to use in processing.
JavaGran is a simple implementation. If after trying it out you are interested in a more complex version, I suggest my PodBuf granulators (MacOS9), or some of the other software resources available on the links page.