In an article about MS new development product for Xbox360 and Windows, a mention of the Amiga is made. I am not sure what is meant by an "Open computer system", but imagine anything is more open than Windows is (and I am not even a usual Windows basher).
:rtfm:
Arstechnica article (see 2nd page)
Arstechnica.com is a good, non-biased PC site. (IMHO) :-)