Write once, run anywhere

From Wikipedia, the free encyclopedia

This article does not cite any references or sources. (August 2007)
Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed.

"Write once, run anywhere" (WORA), or sometimes Write once, run everywhere (WORE), is a slogan created by Sun Microsystems to illustrate the cross-platform benefits of the Java language. Ideally, this means Java can be developed on any device, compiled into a 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 has become an industry standard practice.

This means a programmer can develop code on a PC and can expect it to run on Java enabled cell phones, as well as on routers and mainframes equipped with Java, without any adjustments. This is intended to save software developers the effort of writing a different version of their software for each platform or operating system they intend to deploy on.

The catch is that since there are multiple JVM implementations, on top of a wide variety of different operating systems such as Windows, Linux, Solaris, NetWare, HP-UX, and Mac OS, there can be subtle differences in how a program may execute, which may require an application to be tested on various target platforms. This has given rise to the joke among Java developers, "Write Once, Debug Everywhere"^{[citation needed]}. Another joke, "Write Once, Get Disappointed Everywhere", arose among J2ME developers, also due to the subtle differences of the applications run in different implementations of JVM in mobile devices^[1]. However, for a developer, the abstraction layer that Java provides is usually more convenient than recompiling software for each combination of operating system and architecture that it should run on and still represents a significant reduction in work when developing and supporting an application on multiple platforms.^{[citation needed]}