Of course web pages can be made compatible with any browser.

But first you have to understand that web pages are about content, not about an exact graphic design..
A lot of people don't understand that HTML is NOT DTP
For this reason, graphics designers do not make good web page designers.

One of the worst examples (though it does at least work on any browser) is the page that renders all the text as graphic. You get the fonts and the colours looking the same for everyone, but will take a long time to load and you won't get listed on any search engines. Which is more important?

The aim is not to look the same on all broiwsers, but to look sensible (even if different) on all browsers, and to be useable. There is a craft to that, and it's not about making a rigidly specified design.

By the way, the Greenhouse page looks OK on Galeon, which is a fairly lightweight but very cabable browser for the Linux Gnome desktop.

Anahata