At least with writing uncomplicated web applications it was still quite easy to have it compatible with the major browsers, you just had to test the web applica

At least with writing uncomplicated web applications it was still quite easy to have it compatible with the major browsers, you just had to test the web application with them as you wrote it to make sure. Compatibility problems didn't even come up very much while building it if you stayed reasonably within the boundaries of standards that were well entrenched. The biggest issue was how little CSS IE6 supported, if you did anything fancy with CSS and it didn't work with IE6 you had to include an IE6 specific hack, fortunately that was easy and worked completely fine with other browsers. There were problems with internal off the shelf applications whose user interface was built for IE6 only. The funny thing is those applications still worked well with the Firefox of the time, but IE9 broke compatibility with them and the applications didn't work on IE9, but IE10 got released and was compatible with them again.