I suppose it uses Isotope (http://isotope.metafizzy.co/), since it's the same author.

The JDK8 is available for Linux.

You won't find it in the official repos, though, because they have the OpenJDK implementation. For serious java development you should use the Oracle one.

A reference, linked to by the Ubuntu wiki itself:

http://www.webupd8.org/2012/09/install-oracle-java-8-in-ubun...