Currently, I test on the latest versions of Firefox, Internet Explorer, Netscape, and Opera on Windows; as well as obtaining screenshots in Firefox and Safari for Mac OSx, Internet Explorer versions 5.01, 5.5, 6.0, and 7.0 on Windows, and numerous browsers on Linux.

Older browsers that are not standards- compliant, such as Explorer browser versions prior to 5.01 on Windows, or any version of Internet Explorer on a Mac, are no longer supported. Should your particular audience require such browsers, coding to that level can be discussed, but will require both additional time and expense.