Any computer. Including the one you already own, and none of which are produced by the Linux Foundation.

I will give that driver support for wifi cards may make some computers more awkward than others. It's very rare these days that any common device other than a wifi card or a just this week released graphics card causes problems any more.

(As an aside, how do you escape asterisks here?)

Linus is not forcing you to buy specific hardware to get linux installed. You can't install os x without apple-produced hardware.