This is the tough question that BrowserShots.org web site anwsers for you. They provide a simple way to test your web site in a large variety of configurations and browsers. This is a very nice idea founded on the voluntary help of computers installed all over the world (widely distributed architecture).
This way, you will know how Roumazeilles.net looks on a number of exotic (or not) browsers:
Recommended to any web designer.