They have two systems listed on the site and both are turnkey packages including an iMac by the looks of it. OS X is mostly nice to program for and apple makes

They have two systems listed on the site and both are turnkey packages including an iMac by the looks of it. OS X is mostly nice to program for and apple makes nice hardware. I suspect they could have written the software using C# and windows with a custom PC build somewhat easily, but UNIX is a nice and stable base os so I can see why they might have chosen OS X.