Google is expanding seemingly by the minute, and acquisitions are playing a big role in the search engine leader's quest to rule the technology world. Wednesday Google said it will buy a photo-sharing Web site called Panoramio and confirmed the acquisition of security software vendor GreenBorder Technologies. There are rumors Google will also purchase a provider of online RSS feeds called Feedburner for US$100 million.

In all, Google has agreed to make at least 11 purchases of companies or technologies in the past year. Google usually doesn't release financial terms of small deals, but the big ones are substantial: US$1.65 billion for YouTube and US$3.1 billion for DoubleClick (the latter deal is pending a federal investigation). A little bit more than a year ago, Google spent US$1 billion for a 5 percent stake in AOL.

The past year's purchases, which we describe below, have helped Google shore up gaps in its product line, develop a better office application suite capable of competing with Microsoft Office, and build on its massive success in online advertising. Microsoft has made 13 acquisitions in the same time frame, including a US$6 billion deal during May for aQuantive, a digital marketing and advertising company).

Pending acquisition

April 2007: Google agrees to buy Internet advertising company DoubleClick for US$3.1 billion. Microsoft, which failed in an attempt to buy DoubleClick, urged federal regulators to block the purchase, saying it would hurt competition in Web advertising. The Federal Trade Commission has just launched an antitrust investigation into the Google-DoubleClick deal.

Completed acquisitions

May 30, 2007: Google agrees to buy Panoramio, a community photos Web site based in Spain that connects pictures to the exact geographical location where they were taken, allowing users to view those photographs in Google Earth. Google and Panoramio had already been working together for several months before the purchase, and the deal is expected to lead to further integration of Panoramio content with Google mapping technology.

May 29, 2007: Google buys GreenBorder Technologies, a maker of browser-based security software. The acquisition should help Google strengthen protection against malware across its line of Web applications. "The idea is that these guys have great expertise in the security domain that can provide obvious benefits to Google, its users and its advertisers," a Google spokesman told InfoWorld.

April 2007: Google buys Tonic Systems, which makes technology for creating presentations and document conversion. The purchase is part of Google's strategy to add presentation sharing and collaboration capabilities to Google Docs & Spreadsheets, a competitor of Microsoft Office.

April 2007: Google buys videoconferencing software from Stockholm vendor Marratech. Google plans to use the software for its employees, and has not yet announced any plans to market the videoconferencing technology.

March 2007: Google buys Adscape Media, which makes technology for placing advertisements in video games. The US$23 million deal came less than a year after Microsoft bought video game advertising company Massive for US$200 million, a move that was seen as an attempt by Microsoft to get a leg up on Google in the advertising realm.

March 2007: Google buys Trendalyzer software from a nonprofit called Gapminder. Trendalyzer makes statistics more understandable by converting numbers into interactive animations.

December 2006: For $28 million, Google buys part of Endoxon, an Internet mapping technology company in Switzerland, in a move to bolster European maps in the Google Earth downloadable application and the online Google Maps.

October 2006: Google buys YouTube for US$1.65 billion in a stock transaction. Google subsequently bolstered its video search engine with YouTube content in a move to integrate the two sites. The downside: Google got hit with a US$1 billion lawsuit from Viacom alleging that YouTube enables copyright infringement.

October 2006: Google buys JotSpot, which makes wiki technology for collaborative Web sites. Google's long-term strategy for JotSpot is unclear. New signups for JotSpot stopped after the purchase, and customers are still waiting to hear what Google's plans are for the service, which has suffered from some performance and availability problems since being acquired.

August 2006: Google buys Neven Vision, a company that specializes in mobile photo search. The deal was made to improve Picasa, a free download that helps users share and edit photos, and locate and organize photos on their computers. Neven Vision technology obtains information from photos, such as whether they contain images of people.

(Information from the IDG News Service was used in this report.)