Opera browser is _____ browser and it is a browser with excellent standards support.

Opera browser has historically been marketed as one of the fastest web browsers, particularly known for its speed and excellent standards support. In the era when this question was written (likely mid-2000s to early 2010s), Opera was indeed renowned for performance benchmarks and compliance with web standards. While browser performance varies over time and by use case, 'fastest' is the intended answer in this historical context.