According to Wikipedia: > Up to this point, Opera was trialware and had to be purchased after the trial period ended. Version 5.0 (released in 2000) saw the en

According to Wikipedia: > Up to this point, Opera was trialware and had to be purchased after the trial period ended. Version 5.0 (released in 2000) saw the end of this requirement. Instead, Opera became ad-sponsored, displaying advertisements to users who had not paid for it.[25] Later versions of Opera gave the user the choice of seeing banner ads or targeted text advertisements from Google. With version 8.5 (released in 2005) the advertisements were removed entirely and primary financial support for the browser came through revenue from Google (which is by contract Opera's default search engine). So 2000 through 2005. This seems to be borne out by the more specialized History of the Opera web browser page: > Opera 5, released on December 6, 2000, was the first version which was ad-sponsored instead of having a trial period. [snip] > Version 8.5 was released on September 20, 2005, Opera announced that their browser would be available free of charge and without advertisements from then onwards, although the company still sells support contracts. http://en.wikipedia.org/wiki/History_of_the_Opera_web_browser http://en.wikipedia.org/wiki/History_of_the_Opera_web_browse... http://en.wikipedia.org/wiki/Opera_%28web_browser%29 http://en.wikipedia.org/wiki/Opera_%28web_browser%29