Some information about the sysem that ran BeOS, the BeBox
I'm afraid BeOS seems to have been discontinued in 2009. It has been superseded by Haiku. Both BeOS and Haiku are not 64-bit capable, so almost useless on present day hardware platforms -especially quad 64-bit Opteron systems with 256 GB of memory will give these OS-es too much to handle. You will have a mighty hard time finding a BOINC client for BeOS, probably have to compile it yourself.
But you of course meant DragonFly BSD