There are three major things that has been bothering me in terms of website interoperability testing between browsers. I'm talking about two browser giants: Internet Explorer 7 (IE7) and Firefox (FX).
Pixel Display
I have observed that there is always a difference on the amount of pixel being displayed - at least one pixel. Nothing can be perfect, and looking at the same website on each browser, you get to see no difference at all. But when you get a closer look at it (in between frames or image spaces), you will see that pixel difference.
Sometimes, due to the browser's different pixel-fetching, arrangment of letters in a paragraph also differs. Some of the letters, especially if it contains hypernation, moves up-down as you shift from IE7 to FX.1.1. Font Display
I guess this is probably due to the pixel display of the two different browsers. In Internet Explorer 7, you can see up-close the "emboss-styled" texts. You can easily spot the difference if you are using Firefox's IE Tab Add-On. Upon switching from one tab to another (from IE7 to FX), you can see how the font's display changes from "embossed" to "un-embossed" states.1.2. Horizontal and Vertical Spacing Display
This is again, probably due to the pixel display of two different browsers. As I have mentioned above, opening same sites on two different browsers would only seem to display the same buttons, frames and image spaces. However, upon close inspection, you can easily spot the difference by using Firefox's IE Tab Add-On. For super-techies, you can see the difference by overlaying screenshots (e.g. Photoshop CS3) or by manual screenshot pixel measurment to measure the exact distance or pixel difference.
Loading Time
There is definitely a difference between the two browsers in terms of loading time. Since loading time testing is included in our procedures, I was able to observe how Internet Explorer's loading time is much quicker than that of Firefox. On average, there is around 2 seconds per page difference - given that things or elements are on its usual or normal behaviour.CMS Compatibility
A Content Management System (or CMS) is a program used to create a framework for content of a website. Our company is one of those who are using this tool; and one thing I observed is that some of the functions created (specifically buttons), doesn't work well with Firefox. During one of my testing, I experienced non-functional buttons. I thought at first that this was one of our developers mistake - but later found out that it was due to the tool's incompatibility with Firefox. It was explained to me that some of the heavy-coded scripts embedded on the CMS cannot be properly read by Firefox. But so far in IE7, things worked out just fine.
I am not saying nor implying that one browser is much better than the other. My point here is to simply share my web tester experiences with the two browser giants.
Now my question is, why can't they just follow strict standards (or atleast in proximity)? I mean, I've read some articles in which these two browsers have corresponding or equivalent add-ons and other stuff, but how come in terms of the things I've mentioned above, there is really a difference? It would have been much easier on everyone else's part -- users, developers, designers, and as testers, as well.
Great article!