Welcome to the forums Fluffykins! We also really appreciate your curiosity into how we are creating Chivalry. It’s my hope that we eventually can do a few “making of” blog posts or videos to show off all of our talented folks’ work.
The art team on Chivalry utilize a variety of programs depending on the situation or discipline, but we stick with what Epic (the makers of UDK) recommends. Our environment guys tend to favor 3DS Max for modeling. For creating high-resolution models, we use sculpting program such as Mudbox (my personal favorite) or Z-brush. Our animators use Maya primarily.
These are very broad generalizations of the team, as folks use a variety of plug-ins, third-party utilities, etc. We’re fortunate to be working with UDK, as it is extremely flexible with whatever program you end up using.
Hope I answered your question. Thanks again!