Re:"cleanroom" (Score 2, Interesting)

The reason for the cleanroom in the NEC case was that the Intel chip's design was a trade secret, and, as I recall, NEC was making second-sourcing the Intel chip under an NDA, meaning they'd be hugely liable if they couldn't show a clean reverse engineering process. In the minix case, the source code was published (I have a copy) which means reverse engineering isn't an issue. Only copyright is the issue here, and tha't been disposed of.