Just heard Whit Kemmey speak about "Using XML for Navy Missle Systems". This followed Don's talk on "WS-Why?" -- Don also used the same kind of loud slide deck as Chris.
A couple of interesting things for me about the XML for Missles talk. Whit showed what most considered to be an archaic use of XML as a scripting language as opposed to strictly a data medium. While that may be true, it works for them, and it falls within the confines of the navy's requirements.
The other point that really resonated with me is they only use OSs and code that they not only have the source code for but can also recompile (not Microsoft). Why? From a security perspective, they want to know exactly what every line does, plus they want to be able to put in their own updates and fixes, which not every company wants to allow. It is imperative that the code be known and tested to be reliable. I spoke with Whit afterward, and he mentioned they also code in the patches to the OS themselves rather than rely on the company providing it.
An interesting talk -- along with the liberally scattered pictures of submarines to keep interest high!