Java
From OLSEncyclopedia
Saying Java is nice because it works on all OSes is like saying anal sex is good because it works on all genders.
However, some people mistakenly refer to Javascript as Java. The two are different entities entirely.
Java is a bytecode-compiled language requiring a runtime environment to actually do anything. As such, it isn't powerful enough to compile itself, as any decent programming language can, plus, like all languages with runtime environments, programs written in it have atrocious memory usage.
Java programs in particular are notorious for not looking or acting like the other programs you have running on your computer. Java programmers actually have to go to great lengths to make their applications fit in with the OS they're running on. Java is handy for that exact purpose, though, a program written in Java can run on pretty much any operating system, be it Windows, Mac OS X, or your favorite flavor of Linux.
