Well, I feel like less of a NOOB now... sortof... ;p
It turns out that USARSim is built on an old project to develop a general AI interface for UT bots called Gamebots. Their old site is here:
which has a lot of useful links (though a bit outdated) for ut script programming. Their new sourceforge site actually has the full source for the gamebots mod in subversion:
It would seem, however, that all development on this has halted completely. I think they got it to where it does what they need it to do and moved onto different things. It was an academic project mainly and I know that a few of the authors graduated and moved on to other jobs and whatnot.
Anyway, I was curious to see if I could answer my own question regarding network sockets and so I dug around a bit in the unreal script and found that a few of the classes extend a parent class called TcpLink. I then looked this up in the official documentation for Unreal mod developers:
and poked around in the 2004 section a bit and found the class!
It would appear that UnrealScript allows you to open arbitrary sockets and do whatever you want to with the data as a server or a client. UDP sockets are also supported (duh). Neat!
So, in summary, UnrealScript allows network sockets. They're just built in! The USARSim guys built upon an older project called GameBots and no special licensing was involved! It was just good old fashioned mod hacking and the source code is there plain as day for all to see how it's done.
It's cool... I've been a C++ developer for about 10 years now and have noodled around with Java and Python (the latter I use as my primary scripting interface at work now) and I really appreciate the effort that Epic put into what appears to be a very comprehensive object-oriented language specification (disclaimer: this opinion has been formed by skimming a chapter in the language spec for about 5 minutes... weight it accordingly...)