These are critical times for Microsoft Corp. The company deliberately broke its software licensing model with Thursday's introduction of the unpopular Licensing 6.0, Gavin Clarke writes. Until now customers paid Microsoft's licensing charges, shelling-out hard-won IT budget while complaining of expense and confused details. For Microsoft, this was a reliable - if imperfect - revenue model. After all, what alternatives were there to Microsoft's products? As Microsoft ushered in Licensing 6.0, though, alternatives were - for the first time - emerging. Unfortunately for Microsoft, those alternatives compete in the company's lucrative desktop homeland.