Instead of going with a licensed OS like Windows or VxWorks, they saved tens of dollars. Smart thinking and good use of money in these tough economic times.
It would be nice to see other departments try to realize these types of gains.
Vxworks is tens of thousands of dollars, not tens of dollars. Second, what exactly is the added value of vxworks in this? It is good if you need hard realtime operations, which typically implies a solution with hardware in the loop. If you don't have that (and a flightsim doesn't need it) you can use a non-realtime OS like Linux just fine.
Anyway, how is this news? Where I work we have been writing spacecraft simulators for years on Linux... In the past all that stuff used to run on Sun, but really, what's the point in getting a slow, expensive Sun machine if a cheap Dell box loaded with Suse will do the job faster and cheaper?