>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. 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). https://en.wikipedia.org/wiki/Opera_(web_browser)