While there is obviously a great deal of tension in Microsoft's begrudging support of gays, the gay community doesn't seem to have any bigger endorsement than the one they continually get IBM, listed as #2 in this list of gay-friendly businesses.
I'm surprised you didn't already know, as much as you constantly defend IBM on this forum, but they are not only the tech leader in gay employees, they actually specifically cater to them by placing targeted advertisements in gay magazines. Check out some of this stuff, including their own "out and proud" brochure: