What I call a commercial entity masquerading with a ".org" domain name to gain credibility. In general, a company that wants to sell Foo using some sort of service model can call themselves OpenFoo and put up their site as http://www.openfoo.org The idea is that you seem like a charitable organization even though that trait is only skin deep.
SlashDot is a good example.
Of course, I'm just being overly cynical. Slashdot started off more humbly. And many DotOrgs aren't solely profit driven. Perhaps "comfortable lifestyle" for the owners is the aim. -- SunirShah