Squawk virtual machine on:
[Wikipedia]
[Google]
[Amazon]
Squawk is a 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.
SunSPOTs and Squawk technology PodcastA Java Virtual Machine Architecture for Very Small DevicesThe Squawk Virtual Machine: Java(TM) on the Bare MetalApplication-Driven Customization of an Embedded Java Virtual MachineAhead of time deployment in ROM of a Java-OSProject Sun SpotSquawk Poster
Discontinued Java virtual machines Sun Microsystems software {{software-stub
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 h ...
for embedded system and small devices. Most virtual machines for the Java platform are written in low level native languages such as C/C++
C++ (pronounced "C plus plus") is a high-level general-purpose programming language created by Danish computer scientist Bjarne Stroustrup as an extension of the C programming language, or "C with Classes". The language has expanded significan ...
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 ...
; 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.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
Sunspots are phenomena on the Sun's photosphere that appear as temporary spots that are darker than the surrounding areas. They are regions of reduced surface temperature caused by concentrations of magnetic flux that inhibit convection. Sun ...
* Jikes RVM
Jikes is an open-source Java compiler written in C++. It is no longer being updated.
The original version was developed by David L. "Dave" Shields and Philippe Charles at IBM but was quickly transformed into an open-source project contributed ...
, another JVM written mostly in Java
* Rubinius
Rubinius was an alternative Ruby implementation created by Evan Phoenix. Based loosely on the Smalltalk-80 ''Blue Book'' design, Rubinius sought to
"provide a rich, high-performance environment for running Ruby code."
Goals
Rubinius follows in ...
, a VM for Ruby written in Ruby
* MicroEJ
MicroEJ (pronounced "micro-EDGE") is a French-American software vendor with headquarters in Nantes, France and offices in Boston, Massachusetts, USA. It was founded by Fred Rivard in 2004. It is known for developing MICROEJ VEE, a Virtual Executi ...
VEE, another JVM written mostly in (an extended version of) Java
* List of Java virtual machines
This article provides non-exhaustive lists of Java SE Java virtual machines (JVMs). It does not include every Java ME vendor. Note that Java EE runs on the standard Java SE JVM but that some vendors specialize in providing a modified JVM optimized ...
References
External links
SunSPOTs and Squawk technology Podcast
Discontinued Java virtual machines Sun Microsystems software {{software-stub