Having populated the IT world with Java virtual machines, Sun Microsystems Inc is now seeking to extend Java’s grip by introducing a technology called Jini it claims will simplify the interaction of Java devices with networks. It hopes Jini will lead to the creation of federations of JVMs. Jini is a set of Java class libraries that run on Java, and Sun co-founder Bill Joy told ComputerWire that it will provide a framework for distributed computing that incorporates devices and services. The idea is that Jini will enable client systems and all manner of Java-enabled digital devices to plug into networks and automatically take advantage of available resources without requiring lengthy configuration or interaction with a host operating system. A user of a Jini service or device needs a JVM to run Jini; the client side code being some 500Kb in size and the footprint for an embedded device around 30Kb. A laptop or digital camera user with Jini could plug into a Jini-enabled network and automatically make use of printers, storage, projectors, mail servers and other devices and applications on the network. Jini will also enable processing power to be shared between devices allowing parts of programs to be executed on different devices and for instructions to be shared between them. It’s technology Joy hinted at back at the JavaOne conference when he talked about some of the Java work in SunLabs (CI No 3,392). Sun, which is seeking to extend the ubiquity of the telephone systems’ dial tone to the web, used to refer to that goal as Web Tone but now in a more apparent reflection of its ambitions, calls it Java Tone.

Traffic cop

It’s no wonder Sun continued to champion its lightweight Java-to- Java Remote Method Invocation (RMI) mechanism in the face of industry opposition last year; Jini runs on an enhanced version of RMI which features in the forthcoming JDK 1.2. Sun hopes device builders will embed Jini technology into their systems, thereby making them available to Jini-enabled networks and says it is already working with some 20 partners. Disk drive manufacturer Quantum Corp is one of the first to endorse Jini, and saying it plans to build drives with built-in network connections. Federal Express and Computer Associates are said to be among Sun’s other partners. Jini will be able to run on top of the JavaSpaces mechanism that Sun is creating, which is intended to provide a simple and lightweight infrastructure for developing and deploying networked applications. Indeed both Jini and JavaSpaces projects are informed by the Yale University Linda programming language written by David Gelernter, which use a concept of tuples, collections of data items referenced by name which are placed in and retrieved from a temporary shared memory space. Jini will incorporate a traffic cop look-up facility, enabling services to interact. Sun says it will publish more Jini details on Monday, while evaluation copies of the mechanism, which is plans to ship as freeware like Netscape Communications Corp’s Mozilla (Communicator) code. Jini source should ship in the fourth quarter. Sun says Jini works at a much higher level than existing Java technologies and that it plans to ensure it’ll interoperate with any Java services. Microsoft Corp’s JVM implementation doesn’t support RMI, on which Jini depends, one reason why Sun is pursuing Microsoft through the courts to enforce compliance. Meantime, Microsoft has its own distributed operating system technology called Millennium in the labs. It will supposedly include self-healing features and include a distributed network operating system that removes the boundaries between clients and servers and between the servers themselves, turning the network into a single computer.