Sun is the standard. When a new version of Java (which usually happens about one every quarter or two) and new bug fixes get put out, the Sun JVM has it.

The IBM JVM is an optimized re-write of the JVM. Therefore, it's a tad behind the Sun one. It is faster; and if you want a faster executing system, get the IBM one.

Most people use the Sun JVM for the same reason most people use MS Word... because most people use it. (Except that all those JVM are FREE).

Stephen McConnell