As a web developer, my usual environment when coding is Firefox in my preferred OS of Ubuntu with a 1024 width resolution. But reading through statistics like this, would let you think that you should be coding for Microsoft Platform of at least IE7- the most popular browser there is based on statistics.
Firefox is slowly catching up and what you basically see on Firefox- Ubuntu is the same in Windows – Firefox. So not much problem there until you view your site in Internet Explorer browser specially in IE6. There are still a lot of people using XP until now with IE6 the default browser that comes with it. So IE6 cannot be bypassed in your tests.
But IE6 is hard to code for. There are png transparency issues and unicode html characters not able to render. Even the peso character sign would just be a square in IE6. So I just use either PHP or a peso image. And darn there would be a lot of layout problems you will encounter. (Thankfully there is Xenocode browser sandbox to be able to test your sites in different browsers without the tedious task of installing each version separately.)
To be able to reach out to as many audience, a web developer or designer should definitely check their sites on most browsers.
Jonee, Wacky Long Haired Admin