Top IT companies are continuing to buck the trend of the fragile overall U.S. economy, reporting strong quarterly earnings to kick off 2011. Meanwhile, competition among IT leaders continued to intensify.

After surpassing Microsoft (NASDAQ: MSFT) in both market capitalization and revenue last year, Apple (NASDAQ: AAPL) outdid Microsoft's quarterly profit for the first time in decades. Swift sales of the iPhone--up 113 percent from the year-ago quarter--and the iPad accounted for much of the success.

Despite its new underdog role, Microsoft held its own in the quarter, with revenue and net income increasing 13 percent and 31 percent, respectively, from the same period last year. CFO Peter Klein touted the "strength and breadth of our business," citing the consumer sales of Office 2010, Xbox and Kinect, as well as the continued use of Microsoft platforms and applications in the business world.

Notably, Motorola Mobility (NYSE: MMI), formerly the mobile devices division of Motorola, filed its first quarterly report as a separate, publicly-traded company. In January, Motorola split into two companies, the other being Motorola Solutions, which deals with enterprise mobility and vertical markets such as public safety and government.