When running complex builds that involve many plugins or additional processes
that are spawned by the build, aborting a build leaves these processes running.

An example is a large project we're working on right now, which uses maven2,
graphical unit tests, the vnc plugin, etc...

Stopping a build often leaves sub-processes like VNC instances, surefire and
other stuff running. It would be preferable if hudson were to kill every
sub-process of an aborted build.