The move from IE6/XP to IE8/Win7 and its effect on ASP.NET applications

Question

Hello,

The company I work for is preparing for application testing in IE8. Previously we have been using IE6. Many of our web applications are written in .NET 1.0 and 1.1 with more recent apps written in 2.x and 3.x. I know IE8 has an IE7 compatibility mode and it says it has a quirks mode, but most of our apps were written for 6, which is not specifically mentioned. Compatibility is for 7, which had a compatibility for 6. I do not know if that is necessarily carried over to 8. In 6 quirks mode was to run 5.5 sites without a problem. With no deeper explanation on any of Microsoft's release notes does it mention quirks mode as 6 compliant or even 5.5, just a basis of what it is (specific DOCTYPEs or no DOCTYPEs).

If anyone could shed some light on how sites and apps designed for IE6 should run in IE8 would be greatly appreciated. If anyone else has made a similar move how smooth was the transition?

Thanks.

Answer 1

The only thing you should notice is that you have ensured that your CSS will work correctly in IE8. You can install IE8 in your XP and see what will happen.

ASP.NET code is not important, Pay yout attation on HTML,CSS and JavaScript.

Answer 2

We made a similar switch in our company. We went from IE6 to IE8 across board, the only issues we noticed were related to styling. Now if you decide to upgrade your IIS server than that might cause some of your ASP apps to not work correctly.

Answer 3

Quirks Mode has in principle not changed. IE8+ describes it as “IE5 document mode”. If your pages are still using Quirks Mode, then:

1. rendering should not change much;
2. oh dear. In 2010, really? That's sad.

IE is dragging along bugwards-compatibility for every version of IE since 5.5 except IE6. MS dropped IE6-standards-mode compatibility from IE7, then found the ensuing compatibility problems made it difficult to push people to upgrade to IE7 (and consequently depressed corporate sales of Vista). Since then they've made sure that each IE release has modes to simulate its predecessors, but it was too late to bring back IE6-standards-mode support.

This disastrous mess would never have happened if some idiot hadn't “integrated” the browser with the OS. If it weren't for that we could all just run the standalone IE versions we needed for the apps we needed.

And document rendering mode is only half the story. Getting the JavaScript to work consistently is often more of a problem, especially if the code was a dirty unreliable hack in the first place (which, in the case of webapps aimed at IE6, it often is). On the other hand, webapps that already worked on Firefox and other more standards-compliant browsers should work on IE8 with little to no change.