
Squawk is a
Java
Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mo ...
micro edition virtual machine
In computing, a virtual machine (VM) is the virtualization/ emulation of a computer system. Virtual machines are based on computer architectures and provide functionality of a physical computer. Their implementations may involve specialized har ...
for embedded system and small devices. Most virtual machines for the Java platform are written in low level native languages such as
C/
C++ and
assembler
Assembler may refer to:
Arts and media
* Nobukazu Takemura, avant-garde electronic musician, stage name Assembler
* Assemblers, a fictional race in the ''Star Wars'' universe
* Assemblers, an alternative name of the superhero group Champions of A ...
; what makes Squawk different is that Squawk's core is mostly written in
Java
Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mo ...
(this is called a
meta-circular interpreter). A Java implementation provides ease of portability, and integration of virtual machine and application resources such as objects, threads, and operating-system interfaces.
The Squawk Virtual Machine figure can be simplified as:
* Write as much of the VM in Java as possible
* Targeting small, resource constrained devices
* Enable Java for micro-embedded development
The research project was inspired by
Squeak
Squeak is an object-oriented, class-based, and reflective programming language. It was derived from Smalltalk-80 by a group that included some of Smalltalk-80's original developers, initially at Apple Computer, then at Walt Disney Imagineering ...
. Squawk has a
Java ME
Java Platform, Micro Edition or Java ME is a computing platform for development and deployment of portable code for embedded and mobile devices (micro-controllers, sensors, gateways, mobile phones, personal digital assistants, TV set-top ...
heritage and features a small memory footprint.
A Java Virtual Machine Architecture for Very Small Devices
It was developed to be simple with minimal external dependencies. Its simplicity made it portable and easy to debug and maintain. Squawk also provides an isolated mechanism by which an application is represented as an object. In Squawk, one or more applications can run in the single JVM. Conceptually, each application is completely isolated from all other applications.
See also
* Sun SPOT
* Jikes RVM, another JVM written mostly in Java
* Rubinius, a VM for Ruby written in Ruby
* MicroEJ VEE, another JVM written mostly in (an extended version of) Java
* List of Java virtual machines
References
External links
SunSPOTs and Squawk technology Podcast
A Java Virtual Machine Architecture for Very Small Devices
The Squawk Virtual Machine: Java(TM) on the Bare Metal
Application-Driven Customization of an Embedded Java Virtual Machine
Ahead of time deployment in ROM of a Java-OS
Project Sun Spot
Squawk Poster
Discontinued Java virtual machines
Sun Microsystems software
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