Write once, run anywhere

Write once, run anywhere (WORA), or sometimes write once, run everywhere (WORE), is a 1995^[1] slogan from Sun Microsystems to describe the cross-platform benefits of the Java programming language.^[2][3] It refers to how compiled bytecode from Java source code can run on any system with a compatible Java virtual machine (JVM). In reality, there can be subtle differences in how a program executes due to variability in JVM implementation and host operating system which lead to the comical slogan: Write once, debug everywhere.^[4]

As Java has achieved popularity, the installation of a JVM on chips, devices, and software packages became an industry standard practice.

See also

• Criticism of Java – Criticism of the Java programming language and Java software platform
• Cross-platform software § Challenges
• Free Pascal – Free compiler and IDE for Pascal and ObjectPascal
• Parrot virtual machine – Software to run programming languages
• Software portability – Ability of a program to run on different platforms with little alteration
• Squeak – Object-oriented programming language
• Universal Windows Platform – Computing platform by Microsoft
• Write once, compile anywhere
• Write once, run forever