While UltraHal Assistant is primarily a Windows only product, one or two individuals have reported that they managed to get Hal to run in a Lunix based (wine) environment.
Hal does often make system calls and uses various DLL files as well so there's no real way to judge in advance just how well your individual Hal might or might not run.
I don't recall Robert (Hal's creator) ever saying that he was going to port a version for Linux or other OS's, so for now, it's Windows unless you find a way to kludge it to work with a Linux Distro.
Have fun.