" And, since Exchange works only or best with Windows machines,
the lock-in extends to much else. Linux and Mac boxes get purged
and replaced by Windows ones. Or so goes the story I hear from
folks at big enterprises. So I'm wondering about alternatives. Not
just about applications, but about who's doing what. Is Google
using Exchange? Are Sun, IBM or other open-friendly companies? If
not, what ways have they found around it? What do they give up and
what do they gain?"