So far, LTTng has been mainly integrated in embedded distros: WindRiver Linux, Montavista Linux and STLinux currently ship with LTTng. The interesting news that is particular about Ubuntu here is that, by installing the LTTng packages from PPA, it is now possible to easily deploy the LTTng kernel and userspace tracers on a desktop-oriented distribution.
The K42 project at IBM Research investigated the benefit of a complete OS rewrite with scalability to very large SMP systems in mind. This is an open source operating system supporting Linux-compatible API and ABI.
Their target systems, "next generation SMP systems", back in 2003 seems to have become the current generation of SMP/multi-core systems in the meantime.
It is impossible to enjoy idling thoroughly unless one has plenty of work to do. -- Jerome Klapka Jerome