Really? How can I use JVM on iOS? Is there a good toolchain for Java -> native iOS?

Besides RoboVM [1], there are also other solutions, like Codename One [2] that's based on XMLVM [3], or Avian [4] which is a new and very promising lightweight VM that can also compile code to native. And there's also J2ObcC [5] a compiler that's being developed and used by Google to share code between Android and iOS.

You know, Java can be many things, but you can't beat its ecosystem ;-)

[1] http://www.robovm.org/

[2] http://www.codenameone.com/

[3] http://xmlvm.org/overview/

[4] http://oss.readytalk.com/avian/

[5] http://code.google.com/p/j2objc/

We were talking about servers. A Java program can run on just about every server platform out there, from puniest Windows Server machines all the way to IBM's largest mainframe and Cray's larger supercomputer.

sure there is - RoboVM just came out recently.

In any case, JVM runs on more platforms than any others.