Write once, run anywhere

Last updated

Write once, run anywhere (WORA), or sometimes Write once, run everywhere (WORE), was a 1995 [1] slogan created by Sun Microsystems to illustrate the cross-platform benefits of the Java language. [2] [3] Ideally, this meant that a Java program could be developed on any device, compiled into standard bytecode, and be expected to run on any device equipped with a Java virtual machine (JVM). The installation of a JVM or Java interpreter on chips, devices, or software packages became an industry standard practice.

The catch is that since there are multiple JVM implementations, on top of a wide variety of different operating systems, there could be subtle differences in how a program executes on each JVM/OS combination, possibly requiring an application to be tested on each target platform. This gave rise to a joke among Java developers: Write Once, Debug Everywhere. [4]

In comparison, the Squeak Smalltalk programming language and environment boasts of being truly write once run anywhere, [5] because it runs bit-identical images across its wide portability base. [6]

See also

Related Research Articles

<span class="mw-page-title-main">Java (programming language)</span> Object-oriented programming language

Java is a high-level, class-based, object-oriented programming language that is designed to have as few implementation dependencies as possible. It is a general-purpose programming language intended to let programmers write once, run anywhere (WORA), meaning that compiled Java code can run on all platforms that support Java without the need to recompile. Java applications are typically compiled to bytecode that can run on any Java virtual machine (JVM) regardless of the underlying computer architecture. The syntax of Java is similar to C and C++, but has fewer low-level facilities than either of them. The Java runtime provides dynamic capabilities that are typically not available in traditional compiled languages.

<span class="mw-page-title-main">Java virtual machine</span> Virtual machine that runs Java programs

A Java virtual machine (JVM) is a virtual machine that enables a computer to run Java programs as well as programs written in other languages that are also compiled to Java bytecode. The JVM is detailed by a specification that formally describes what is required in a JVM implementation. Having a specification ensures interoperability of Java programs across different implementations so that program authors using the Java Development Kit (JDK) need not worry about idiosyncrasies of the underlying hardware platform.

<span class="mw-page-title-main">Smalltalk</span> Object-oriented programming language released first in 1972

Smalltalk is a purely object oriented programming language (OOP) that was originally created in the 1970s for educational use, specifically for constructionist learning, but later found use in business. It was created at Xerox PARC by Learning Research Group (LRG) scientists, including Alan Kay, Dan Ingalls, Adele Goldberg, Ted Kaehler, Diana Merry, and Scott Wallace.

<span class="mw-page-title-main">Virtual machine</span> Software that emulates an entire computer

In computing, a virtual machine (VM) is the virtualization or emulation of a computer system. Virtual machines are based on computer architectures and provide the functionality of a physical computer. Their implementations may involve specialized hardware, software, or a combination of the two. Virtual machines differ and are organized by their function, shown here:

In computing, cross-platform software is computer software that is designed to work in several computing platforms. Some cross-platform software requires a separate build for each platform, but some can be directly run on any platform without special preparation, being written in an interpreted language or compiled to portable bytecode for which the interpreters or run-time packages are common or standard components of all supported platforms.

In computing, just-in-time (JIT) compilation is compilation during execution of a program rather than before execution. This may consist of source code translation but is more commonly bytecode translation to machine code, which is then executed directly. A system implementing a JIT compiler typically continuously analyses the code being executed and identifies parts of the code where the speedup gained from compilation or recompilation would outweigh the overhead of compiling that code.

Rhino is a JavaScript engine written fully in Java and managed by the Mozilla Foundation as open source software. It is separate from the SpiderMonkey engine, which is also developed by Mozilla, but written in C++ and used in Mozilla Firefox.

SableVM was a clean room implementation of Java bytecode interpreter implementing the Java virtual machine (VM) specification, second edition. SableVM was designed to be a robust, extremely portable, efficient, and fully specifications-compliant Java Virtual Machine that would be easy to maintain and to extend. It is now no longer being maintained.

HotSpot, released as Java HotSpot Performance Engine, is a Java virtual machine for desktop and server computers, developed by Sun Microsystems which was purchased by and became a division of Oracle Corporation in 2010. Its features improved performance via methods such as just-in-time compilation and adaptive optimization. It is the de facto Java Virtual Machine, serving as the reference implementation of the Java programming language.

Java Card is a software technology that allows Java-based applications (applets) to be run securely on smart cards and more generally on similar secure small memory footprint devices which are called "secure elements" (SE). Today, a secure element is not limited to its smart cards and other removable cryptographic tokens form factors; embedded SEs soldered onto a device board and new security designs embedded into general purpose chips are also widely used. Java Card addresses this hardware fragmentation and specificities while retaining code portability brought forward by Java.

<span class="mw-page-title-main">Java (software platform)</span> Set of computer software and specifications

Java is a set of computer software and specifications that provides a software platform for developing application software and deploying it in a cross-platform computing environment. Java is used in a wide variety of computing platforms from embedded devices and mobile phones to enterprise servers and supercomputers. Java applets, which are less common than standalone Java applications, were commonly run in secure, sandboxed environments to provide many features of native applications through being embedded in HTML pages.

<span class="mw-page-title-main">Squawk virtual machine</span>

Squawk is a Java micro edition virtual machine 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; what makes Squawk different is that Squawk's core is mostly written in Java. A Java implementation provides ease of portability, and integration of virtual machine and application resources such as objects, threads, and operating-system interfaces.

In computer programming, a green thread is a thread that is scheduled by a runtime library or virtual machine (VM) instead of natively by the underlying operating system (OS). Green threads emulate multithreaded environments without relying on any native OS abilities, and they are managed in user space instead of kernel space, enabling them to work in environments that do not have native thread support.

<span class="mw-page-title-main">Software portability</span> Ability of a program to run on different platforms with little alteration

Software portability is a design objective for source code to be easily made to run on different platforms. An aid to portability is the generalized abstraction between the application logic and system interfaces. When software with the same functionality is produced for several computing platforms, portability is the key issue for development cost reduction.

Memory footprint refers to the amount of main memory that a program uses or references while running.

Eclipse OpenJ9 is a high performance, scalable, Java virtual machine (JVM) implementation that is fully compliant with the Java Virtual Machine Specification.

The Java Development Kit (JDK) is a distribution of Java technology by Oracle Corporation. It implements the Java Language Specification (JLS) and the Java Virtual Machine Specification (JVMS) and provides the Standard Edition (SE) of the Java Application Programming Interface (API). It is derivative of the community driven OpenJDK which Oracle stewards. It provides software for working with Java applications. Examples of included software are the Java virtual machine, a compiler, performance monitoring tools, a debugger, and other utilities that Oracle considers useful for Java programmers.

Java bytecode is the instruction set of the Java virtual machine (JVM), the language to which Java and other JVM-compatible source code is compiled. Each instruction is represented by a single byte, hence the name bytecode, making it a compact form of data.

GraalVM is a Java Development Kit (JDK) written in Java. The open-source distribution of GraalVM is based on OpenJDK, and the enterprise distribution is based on Oracle JDK. As well as just-in-time (JIT) compilation, GraalVM can compile a Java application ahead of time. This allows for faster initialization, greater runtime performance, and decreased resource consumption, but the resulting executable can only run on the platform it was compiled for.

References

  1. ↑ "Write once, run anywhere?". ComputerWeekly.com. Retrieved 2022-10-05.
  2. ↑ "JavaSoft ships Java 1.0". Sun Microsystems. 1996-01-23. Archived from the original on 2007-03-10. Java's write-once-run-everywhere capability along with its easy accessibility have propelled the software and Internet communities to embrace it as the de facto standard for writing applications for complex networks
  3. ↑ "Write once, run anywhere?". Computer Weekly. 2002-05-02. Retrieved 2009-07-27.
  4. ↑ Wong, William (2002-05-27). "Write Once, Debug Everywhere". electronicdesign.com. Retrieved 2013-02-04. So far, the "Write-once, run-everywhere" promise of Java hasn't come true. The bulk of a Java application will migrate between most Java implementations, but taking advantage of a VM-specific feature causes porting problems.
  5. ↑ "Welcome To Squeak". Squeak. Retrieved 5 May 2015.
  6. ↑ "Back to the Future The Story of Squeak, A Practical Smalltalk Written in Itself". Dan Ingalls Ted Kaehler John Maloney Scott Wallace Alan Kay. Retrieved 5 May 2015.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.