Which browser powered the Wii's Internet Channel?

The Wii’s Internet Channel was powered by the Opera browser.

Nintendo developed the Internet Channel in partnership with Opera Software. It was a version of Opera adapted for the Wii, with an interface designed for television viewing and navigation using the Wii Remote rather than a traditional mouse-and-keyboard setup.

A trial version appeared on December 22, 2006, followed by the final release on April 11, 2007. The browser supported ordinary web technologies such as HTML, CSS, JavaScript, and Adobe Flash, though its capabilities were limited by the Wii’s hardware and the eventual decline of Flash. It was not Chrome, Safari, or Firefox; those browsers did not power the Wii’s built-in Internet Channel.