Forum Moderators: open
good luck
regards
henry
When I do a new website I open it and see if it doesn't crash netscape 4x, but the main thing you need to check on netscape 4 is that your dom javascript, if you use it, is correctly escaped so it doesn't pop up an endless series of javascript errors.
IE 5.01 SP2 on Win98SE
IE 6 (quirks and strict); Netscape 6.01 & 7.02; Opera 5.0, 6.0 & 7.54; Firefox 0.9 on WinXP
IE 5.0 & 5.2; Safari 1.0 (or OmniWeb 5) & 1.2; Netscape 7; Mozilla 1.7; Opera 6 on MacOS
Konqueror 3; Netscape 7; Mozilla 1.7 on Linux
Plus visual checks in IE 4 and Netscape 4.8
Admittedly a long and over-cautious list. You could ditch the old versions of Opera and anything by Netscape. You could also lose IE 4 and possibly even IE 5.0 and still be relatively safe.
Windows
Mac
Linux
Platform-neutral
Extras (only if specifically required - otherwise check the site is readable but don't worry about the layout)
NOT required
Useful resources
Evolt Browser Archive [browsers.evolt.org]
How to: Install multiple versions of IE on your PC [webmasterworld.com]