What is classpath hell and is/was it really a problem for Java?

Question

What is classpath hell and is/was it really a problem for Java?

Answer 1

This is a somewhat more concrete example:

When two libraries (or a library and the application) require different versions of the same third library. If both versions of the third library use the same class names, there is no way to load both versions of the third library with the same classloader.

Take a loot at http://en.wikipedia.org/wiki/Java_Classloader#JAR_hell for more examples.