The long awaited Opera 7 Beta 1 has been released. Note that many (though not all) of the scripts on this site now function in Opera 7. This includes the DOM TS although Opera 7 does have a tendency to crash. Opera 7 is much improved over earlier versions. It's DOM Core/HTML/Style implementation is now modelled after the W3C Standards and it's support for CSS 1 and 2 exceeds that of Internet Explorer 6. Opera 7 still does not yet achieve the same level of support for the CSS and DOM Standards as Mozilla or Netscape 7. Hopefully Opera will fix these problems before releasing Opera 7 final.
Unfortunately, due to the numerous unimplemented CSS features in Internet Explorer 6, and the somewhat buggy implementation found in Opera 7, we have not yet reached the point where a web author can develop to the standards and have their content behave and appear the same in all modern browsers.
It was necessary to experiment with the implementations of Mozilla, Internet Explorer 6 and Opera 7 Beta 1 in order to get the menu implementations to even come close to working. If you are interested you can find the experiments: