Different Linux and Ubuntu releases have different software included by default -- for example, transmission, Firefox, and Banshee have all been default applications.
As far as I know, most of these applications have been developed using C, or C++ (vala also), or another language that will be compiled into native Linux binary files.
Is there any software which has been developed in Java and has become one of Ubuntu's default apps? (Excluding some IDEs such as NetBeans and Eclipse.)