Opera
Opera is a Norwegian web browser created by Opera Software ASA. It uses the Presto engine to present web pages. Historically, it's been known to be quick at implementing new features, such as being very early with tabbed browsing.
Opera is an implementation of JavaScript.
Other implementations of JavaScript.
Opera is an implementation of HTML.
Other implementations of HTML.
JavaScript implementations
The latest version of Opera uses a JavaScript engine called Carakan.