Sun Microsystems Inc’s JavaSoft unit has released the specification of its PersonalJava slimmed-down version of the caffeinated language for public comment. PersonalJava was announced at JavaOne at the start of April as a version of the language to be used in television set-top boxes, screen phones and game consoles. Its sister skinny Java, EmbeddedJava, is even smaller and is meant for low-end phones, printers, and pagers – things that only require character-based interfaces. Sun worked with WebTV Networks Inc and Lucent Technologies Inc, among others on the spec, but was not willing to talk about either of those or what work had been done. WebTV became the first licensee of the technology before JavaOne, but that was before Microsoft Corp bought it. PersonalJava comprises classes, Beans, APIs and a Personal Abstract Windowing Toolkit, to sit on top of an operating system, which is not included. The idea is that vendors will port the code, when it is finalized, to whatever operating system they choose. Sun says this is the best approach given the number of proprietary operating systems there are in the embedded space. The PersonalJava 1.0 spec is a subset of the Java Developer’s Kit (JDK) 1.1. It is missing some of the things that are specific to desktop applications, such as classes dealing with enterprise- class messaging, database access, and so on. Everything produced that is compatible with PersonalJava will be forward compatible with the JDK, says Sun. The target size for PersonalJava is 2Mb ROM, but 1MB ideally, and should be able to run using a processor with no more than 50MHz clock speed. After a comment period of at least 60 days, Sun will freeze the code, which it says it will do by December. It will be ready to license the source code by the year-end, and plans reference implementation early next year. As ever with roadmaps, this one already deviates significantly from the one produced at JavaOne. Sun is also preparing a set of tools to go with PersonalJava that will be enhancements to the JDK. These include a pre-compilation tool that will tell developers whether the code they are developing is appropriate for their target device. There will be a so-called ROM-izer tool, which optimizes the code for putting it into ROM, and a tool to estimate the size of compiled code before it is fully written. The tools will be available as add-ons to the JDK in December, and will be included in the next version after that. The spec is posted at https://java.sun.com/products/personaljava
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