Node creation and editing slow in Internet Explorer? Here is a solution ...
A client recently asked us for help with a very specific issue. The node edit page was hanging up, but only in Internet Explorer 10, and not in Firefox or Chrome. The client had WYSIWYG editor enabled.
This automatically pointed to a front end issue, not a server issue.
So, we investigated more, and found that the underlying issue is between Internet Explorer and JQuery with a large number of items to be parsed.