Java

Write once, run everywhere
The success of Java itself would be in slow, deliberate entrenchment in the oatmeal world of enterprise software, the long-lasting collections of programs that together serve the needs of whole organizations. The Java language promised "write once, run anywhere" functionality, that is, code written for the JVM would run the same regardless of the underlying machine or operating system.

Software companies spend a fortune building separate code for Windows NT, Windows 3.1, Linux, MacOS, Solaris, AIX, etc. This is a major headache for every IT shop. Java has achieved the greatest success in letting developers write Java code once for all platforms.