I'm a doctor, not a mechanic
The Deus Ex Conversation Editor.
This comes with the SDK, and allows you to define new Conversations for your levels.
The resulting package looks like a whole mess of raw Conversation and child objects, how these are arranged, and how the game decides to associate Conversations with Actors, I don't know.
Since the compiler "mangles" the format somewhat to get it into a package, you can't just extract the raw .CON file back out again.
I've been playing with extracting the raw object contents into an XML file, and this has proven promising.
It may be possible to write something that converts this exported text file (or maybe a raw Unreal object) into a .CON file, but we'd have to figure out the file format (Any takers?).
Xhiris: Does this belong in Category Application? It only does the one thing, and only for this game. I think of it more as a part of the SDK than it's own thing, thoughts?
Tarquin: it still counts as a program that does stuff :) Won't hurt to list it in that category. There are other apps that are highly specialised too.