I’m currently developing a moderately large sized web app with ASP.NET 2.0 that uses a lot of jQuery/jQueryUI for things like tabs, modal dialogs, and general client-side coolness. We’ve got it running on our test area now, but IE7 and IE8 are performing very poorly with all the page setup that needs to happen for the tabs and modal dialogs. On one of our older laptops (Dell, 3 or 4 years old), it’s approximately 3 to 5 seconds to load the page from the test server over our internal network (wireless), both the first time and on postbacks. Firefox 5 takes 1 or 2 seconds on the same machine. Running SunSpider on IE8 and FF5 confirms that FF5 is almost 18 times faster with javascript. I know there’s dispute about the real-world value of stuff like SunSpider, but that’s a big gap no matter how you slice it.
My question is this: how is classic IE (7 and 8) generally handled when developing web apps that involve a significant amount of javascript processing? Is bad performance OK? If so, to what degree?
My kneejerk reaction is to treat IE-classic as the exception. It’s going away (Google apps will soon drop support, and IE9 is an automatic update for Windows Vista and 7), and cannot be considered part of the modern web as an application platform. It needs to work because it’s still a large portion of the browser share, but some small layout and performance issues are OK. I’ve heard before that “performance is a feature“, but that can’t be a reality for all users and platforms.
UPDATE, to clarify: this is for the general internet, not for an internal network at a company that’s still running IE7 only.
The only answer to this question is: “Who is your target user/demographic and what browsers are they using?”
If your app is for a large global bank and their employees, assume they are ALL running 4 year old Dells with Windows XP and IE6 with a 14″ monitor.
If your app is for the public at large, then I say ‘good riddance’ to IE8 and below. You shouldn’t have to accommodate a faulty platform at the expense of everyone else using a modern supported browser.