Also, the 32bit work and the Iyonix abstraction layer came from the RISC OS 5 they acquired from Pace. And the USB stuff is at least partly derived from FreeBSD and NetBSD. And you're not going to get near proper USB2 speeds with the Iyonix motherboard anyway (although it's much faster than USB1). Search on drobe for articles about it.
But anyway, fair play to Castle. Don't confuse facts and rational thought with bashing, though.