JavaOS
Encyclopedia
JavaOS is an operating system
with a Java virtual machine
as a fundamental component. It was jointly developed by Sun Microsystems
and IBM
. Unlike Windows, Mac OS, Unix
or Unix-like
systems which are primarily written in the C
programming language, JavaOS is primarily written in Java.
As of 2006, Sun considers JavaOS a legacy system
.
. The Java virtual machine runs on top of the microkernel.
Platforms that the kernel runs on include:
All device driver
s are written in Java and executed by the virtual machine.
A graphics and windowing system, implementing the AWT
API
is also written in Java.
s and has applications in devices such as set top boxes, networking
infrastructure and ATMs. It's also the operating system that comes with the JavaStation
.
and recommends migration
to Java ME. This by itself however is not a full replacement, as Java ME is an API
specification, which runs on top of an operating system, and is not an operating system in
itself.
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
with a Java virtual machine
Java Virtual Machine
A Java virtual machine is a virtual machine capable of executing Java bytecode. It is the code execution component of the Java software platform. Sun Microsystems stated that there are over 4.5 billion JVM-enabled devices.-Overview:...
as a fundamental component. It was jointly developed by Sun Microsystems
Sun Microsystems
Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
and IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
. Unlike Windows, Mac OS, Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
or Unix-like
Unix-like
A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification....
systems which are primarily written in the C
C (programming language)
C is a general-purpose computer programming language developed between 1969 and 1973 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system....
programming language, JavaOS is primarily written in Java.
As of 2006, Sun considers JavaOS a legacy system
Legacy system
A legacy system is an old method, technology, computer system, or application program that continues to be used, typically because it still functions for the users' needs, even though newer technology or more efficient methods of performing a task are now available...
.
Design
The system is based on a hardware architecture native microkernelMicrokernel
In computer science, a microkernel is the near-minimum amount of software that can provide the mechanisms needed to implement an operating system . These mechanisms include low-level address space management, thread management, and inter-process communication...
. The Java virtual machine runs on top of the microkernel.
Platforms that the kernel runs on include:
- ARMARM architectureARM is a 32-bit reduced instruction set computer instruction set architecture developed by ARM Holdings. It was named the Advanced RISC Machine, and before that, the Acorn RISC Machine. The ARM architecture is the most widely used 32-bit ISA in numbers produced...
- PowerPCPowerPCPowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...
- SPARCSPARCSPARC is a RISC instruction set architecture developed by Sun Microsystems and introduced in mid-1987....
- StrongARMStrongARMThe StrongARM is a family of microprocessors that implemented the ARM V4 instruction set architecture . It was developed by Digital Equipment Corporation and later sold to Intel, who continued to manufacture it before replacing it with the XScale....
- IA-32IA-32IA-32 , also known as x86-32, i386 or x86, is the CISC instruction-set architecture of Intel's most commercially successful microprocessors, and was first implemented in the Intel 80386 as a 32-bit extension of x86 architecture...
All device driver
Device driver
In computing, a device driver or software driver is a computer program allowing higher-level computer programs to interact with a hardware device....
s are written in Java and executed by the virtual machine.
A graphics and windowing system, implementing the AWT
Abstract Window Toolkit
The Abstract Window Toolkit is Java's original platform-independent windowing, graphics, and user-interface widget toolkit. The AWT is now part of the Java Foundation Classes — the standard API for providing a graphical user interface for a Java program.AWT is also the GUI toolkit for a...
API
Application programming interface
An application programming interface is a source code based specification intended to be used as an interface by software components to communicate with each other...
is also written in Java.
Applications
JavaOS was designed to run on embedded systemEmbedded system
An embedded system is a computer system designed for specific control functions within a larger system. often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. By contrast, a general-purpose computer, such as a personal...
s and has applications in devices such as set top boxes, networking
Computer network
A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
infrastructure and ATMs. It's also the operating system that comes with the JavaStation
JavaStation
The JavaStation was a Network Computer developed by Sun Microsystems between 1996 and 2000, intended to run only Java applications.The hardware is based on the design of the Sun SPARCstation series, a very successful line of UNIX workstations....
.
Future
Sun now officially considers JavaOS a legacy systemLegacy system
A legacy system is an old method, technology, computer system, or application program that continues to be used, typically because it still functions for the users' needs, even though newer technology or more efficient methods of performing a task are now available...
and recommends migration
to Java ME. This by itself however is not a full replacement, as Java ME is an API
specification, which runs on top of an operating system, and is not an operating system in
itself.
See also
Other implementations of Java based operating systems:- JNodeJNodeJNode is a free software project to create a Java platform operating system. The project has taken the unique direction of creating all the software in Java itself, with the exception of some assembly language to boot and load the system...
- Open source project creating a Java based OS written entirely in Java (and machine code) - JX (operating system)JX (operating system)JX is a microkernel operating system with both the kernel and applications implemented using the Java programming language.- Overview :JX is implemented as an extended Java Virtual Machine , adding support to the Java system for necessary features such as protection domains and hardware access,...
- Operating system written in Java - SanosSanosFor the Macedonian bus industry from Skopje, see FAS Sanos.Sanos is a minimalistic 32-bit x86 operating system kernel for network server appliances running on standard PC hardware...
- Minimalist kernel designed to run Java (and C) server applications - SavaJeSavaJeSavaJe was the developer of the SavaJe OS, a Java OS for advanced mobile phones.The SavaJe OS was a monolithic OS-and-Java platform, an implementation of Sun Microsystems' Java Standard Edition, as opposed to...
- Mobile phone OS designed to run Java SE applications - JOS - A free Java based operating system
External links
- Press release announcing JavaOS (May 29, 1996)
- JavaOS SDK page java.sun.com
- Press release announcing the demise of JavaOS