[e2e] Virtual Hosts (BSD/Linux Stacks) in User Space?

[Shivkumar Kalyanaraman]

Folks,

We would like to cut our cycle times for developing prototypes, and be
able to experiment with a large number of network nodes. But we are
limited by kernel programming vagaries, and the number of physical nodes
in our lab testbed.

I have heard that folks (esp in startups) have ported BSD and Linux stacks
so that several virtual machines can be instantiated in a single machine.
This way when we crash the virtual machine, we wont crash the physical
machine. And we can instantiate several of these to emulate fully featured
prototypes and get significantly different information that what is
possible in simulation...

Now the question: do such software exist in the public domain? My
requirements are slightly different in scope from what's provided in Jay
Lepreau's incredible Emulab facilty.
http://www.emulab.net/index.php3

best
-Shiv
===
Shivkumar Kalyanaraman
Associate Professor, Dept of ECSE, Rensselaer Polytechnic Institute (RPI)