What are the best practices for cross-browser web sites? [closed]

Question

Use a library like jQuery abstract away the differences in the DOM, AJAX and JavaScript.

Make sure you're keeping HTML, CSS and Javascript in separate files as much a possible. Mixing structure, presentation and behavior in your HTML file just makes finding and fixing problems harder.

Use Firebug in Firefox for:

• Debugging/stepping through your JS.
• Seeing how your stylesheets are being interpreted and hacking them up on the fly to see how to fix your problem.
• See how many calls you are making for remote resources and how long they take.
• Profile your code.

Chrome and IE8 have similar tools built-in that can be used for the same thing.

Opera and Safari (and IE) have Firebug Lite.

1. Use CSS Reset on start of your stylesheet...

   You can get one here...

2. Validate your code by w3c ...

   You can validate your code here by page link or simply copy paste page element