Opera, a Web browser with a small, but loyal, core group of 300-million users, surprised everyone when they moved from its Presto Web rendering engine to the popular open-source Webkit engine. Webkit is best known for being Google’s Chrome and Apple’s Safari Web engine.
Web engines are what take Web page content such as HTML files, and formatting instructions, for example Cascading Style Sheets (CSS), and transform these into the page you see on your screen. They are a Web browser’s heart. For Opera, this is no less than a heart transplant.