A much more significant difference between Opera and either IE or Navigator is market share. Opera has virtually none. But then, neither does any other browser besides the big two. However, not only does Opera offer some unusual and useful features, but the browser's core could show up in Internet appliances. One of those features allows end users to take back some control over the browsing experience.
Power users can configure the browser to their liking.
With version 4.0, cookies can be displayed and filtered. Hence, cookie abuse can be lessened by cutting off the source of the problem. It's a feature being incorporated into the pending releases of other browsers. Opera also sports other user-friendly features, such as multiple windows and full keyboard navigation. The last stands for Wireless Markup Language, the standard for such things as wireless Web phones.