On the last Friday of Campus-Party 2009, Pedro Reis and me (Marcelo Arbore) have performed a presentation together.
He talked about Zones, which is an O.S. abstraction for instantiating systems, allowing multiple applications to run isolated one from each other in the same system.

I showed some concepts and a brief demonstration on DTrace, which is a dynamic tracing framework for OpenSolaris that provides an infrastructure to allow administrators and developers to concisely answer arbitrary questions about the behavior of the operating systems and user programs (from the kernel to high level). The questions are written in a script C-like language called D.

Here you can see a blog post showing a DTrace demonstration:

http://blogs.sun.com/arbore/entry/basic_demonstration_of_dtrace_feature