The competition between Microsoft and Sun Microsystems could be described as "passionate" -- and that’s just the companies' ice hockey teams. The two teams will face off Sunday in Seattle’s Key Arena in one of the featured games of the Microsoft Hockey Challenge tournament. What’s at stake is company pride and much more -- they’ll be playing to help raise $1 million for the Ronald McDonald House in Seattle. The story of how the two software rivals became ice hockey combatants, and how Microsoft got a hockey team in the first place, is folklore around Redmond, says Nadine Kano of the Windows division at Microsoft. It all began just three years ago, when Canadian and American Microsoft employees working on Microsoft’s mail server, Exchange, had their own exchange of what Kano describes as "some harsh words." The exact words are long forgotten, but the means of settling the dispute lives on. The two sides brought out their hockey sticks, laced up their skates and settled it on the ice. It didn’t matter that Brian Valentine, now senior vice president of the Windows division and then-goalie for the American side, didn’t know how to skate. The Canadians let him stand on a strip of artificial turf, and they still won.