Anyone keeping score? Cisco since March 13 has announced plans to acquire three very different companies and completed the acquisition of a fourth.

This week Cisco announced it is acquiring network processor start-up SpansLogic for an undisclosed amount. Not much is known about the start-up's work - just that it intends to improve network efficiency and throughput.

Earlier this month Cisco said it is buying NeoPath Networks, also for an undisclosed amount. That company makes appliances to aggregate data on network-attached storage and file servers, in a growing area called file area networking.

Then of course there was the recent news that Cisco would buy WebEx, for a very highly disclosed amount, $3.2 billion. That acquisition transforms the company into a networked applications vendor that competes more directly with Microsoft.

The deal that closed was Cisco's purchase of Reactivity, a maker of XML gateway and security hardware, for $135 million.

Growth through acquisition is nothing new for Cisco; in fact, the company is probably one of the best at managing acquisitions and using the acquired companies to its advantage. As Network World noted, 2006 was a pretty tame year for Cisco acquisitions, at just $256 million worth. So, perhaps Cisco had some pent-up demand that prompted it to get 2007 off to a fast start.

What does it all mean? Cisco isn't forgetting to purchase a little innovation in its bread-and-butter business of network routing and switching, as the SpansLogic buy shows.

But it is also buying its way into new markets - into applications, with WebEx, and into storage, with NeoPath and other acquisitions. The makeup of the company continues to evolve, and there is little the company doesn't touch in the world of networking.

Jeff Caruso is site editor at Network World.