Put simply, Puppet is a system for automating system administration tasks. To learn more, read our big picture overview of Puppet, or take a deeper look at what Puppet can do with the Puppet Introduction. There's also an about Puppet page which gives the highlights of Puppet's functionality.
SwitchPipe is a proof of concept "Web application server" or, more accurately, a Web application process manager and request proxy. Backend Web applications are loaded into their own processes, making SwitchPipe language agnostic. HTTP requests are proxied at the TCP level using information extracted from the headers to establish which backend application is being demanded.
R. Popp, D. Montana, R. Gassner, G. Vidaver, and S. Iyer. IEEE International Conference on Systems, Man, and
Cybernetics, 3, page 2184--2189. San Diego, CA USA, IEEE, (11-14 October 1998)