Sun revises PersonalJava

Sun Microsystems has released a new, less memory-intensive version today of PersonalJava, the stripped-down version of the company's "write once, run anywhere" Java technology.

PersonalJava, as it skipped straight from version 1.1.1 to version 3.0 today, picked up "Truffle," a took kit that lets Java programs use pre-built graphical elements so it's easier to develop interfaces for PersonalJava devices.

Truffle improves PersonalJava's customizability while using less memory than previous techniques, Sun said. Memory is a precious resource in the extremely cost-conscious and space-constrained world of consumer electronics devices. Truffle also adds Sun's "touchable" elements to make PersonalJava easier to use on touch screens.

Sun executives said the new version of PersonalJava can run Jini, Sun's Java-based networking software that lets anything automatically connect to a network and share resources.

PersonalJava consists chiefly of a small Java virtual machine (JVM), a software module that lets Java programs run on a variety of different types of hardware. PersonalJava is intended for consumer devices such as Web phones or set-top boxes that are attached to networks.

EmbeddedJava serves a similar function--providing an environment for Java programs to run on small electronic devices--but EmbeddedJava is intended to perform specific, predefined tasks. PersonalJava is intended to have more general abilities. Sun released EmbeddedJava 1.0 in January.

Both EmbeddedJava 1.0 and PersonalJava 3.0 will be available under Sun's new Community Source License, which lets people see and modify the underlying source code for free. Developers must send bug fixes back to Sun, but otherwise retain intellectual property rights to their own modifications. However, before companies may sell products, they must pay Sun a fee.

However, PersonalJava 3.0 doesn't yet comply with the latest version of its big brother, Java 2. Instead, people developing PersonalJava programs must use an earlier version of Java called Java Development Kit 1.1.7b. A similar lag afflicted some people trying to get Sun's "spontaneous networking" technology Jini to work with Java 2, but Sun got Jini revved up to Java 2 when it was officially released January 25.

Sun skipped version 2.x of PersonalJava to avoid confusion with the renumbering of Java overall. Sun changed the name of the Java Development Kit 1.2 to Java 2 in December.