Server and Tools revenue increased mainly reflecting growth in product revenue. Product revenue increased $652 million or 6%, driven primarily by growth in Windows Server, SQL Server and Enterprise CAL Suites revenue, reflecting increased revenue from annuity volume licensing agreements and continued adoption of Windows platform applications, offset in part by a decline in developer tools revenue. Enterprise Services revenue was relatively flat, with growth in Premier product support services nearly offset by decreased consulting services.

Server and Tools operating income increased due mainly to revenue growth and reduced research and development expenses, offset in part by increased cost of revenue. Research and development expenses decreased $38 million or 2%, primarily driven by reduced third-party development and programming costs and headcount-related expenses, offset in part by increased hosting, localization and lab costs. Cost of revenue increased $25 million.