Presto was the browser engine of the Opera web browser from the release of Opera 7 on 28 January 2003, until the release of Opera 15 on 2 July 2013, at which time Opera switched to using the Blink engine that was originally created for Chromium.[3] Presto was also used to power the Opera Mini and Opera Mobile browsers.
Presto is a dynamic engine. Web pages can be re-rendered completely or partially in response to DOM events. Its releases saw a number of bug fixes and optimizations to improve the speed of the ECMAScript (JavaScript) engine. It is proprietary and only available as a part of the Opera browsers.
ECMAScript engines
A succession of ECMAScript engines have been used with Opera. (For the origin of their names, see Cultural notes below.) Pre-Presto versions of Opera used the Linear A engine. Opera versions based on the Core fork of Presto, Opera