Multiplatform: Java was branded with the slogan "write once, run anywhere" (or WORA), and that still holds true today. Java programming code written for one platform, like the Windows operating system, can be easily transferred to another platform, like a mobile phone OS, and vice versa without being completely rewritten. Java works on multiple platforms because when a Java program gets compiled, the compiler creates a .class bytecode file that can run on any operating system that has the Java virtual machine (JVM) installed on it. It's typically easy to install JVM on most major operating systems, including iOS, which was not always the case.