Google Unified Search is a very interesting search add-on for the Firefox web browser. You might have read about add-ons that combine Google search results with those of other search engines such as Bing or Wolfram Alpha. Google Unified Search takes that concept a step further by integrating multiple search engines in Google results. It adds support for Bing, Wikipedia, Wolfram Alpha, Stumbleupon and Delicious in the Google search results.

Search results of one search engine besides Google Search are displayed at a time but it is possible to switch to the results of another one without having to reload the page. By default Google search results and Bing search results are displayed in the interface. A control in the top right corner makes it possible to switch the alternative search engine to another one.

A left click on a search result in the Google column will open the website as usual. A click on a result in the alternative search engine on the other hand will open the result just in the area of that search engine. Users who want to open the website normally will have to open it in a new tab or window instead.

Google Unified Search is an excellent way of displaying additional information about a search term in the Google search results.