This doesn't concern .Net except that the browser is the client for ASP.NET.  Some praise Firefox and other browsers for tabbed browsing, and I think that this is a feature that shouldn't be lacking from IE. 

I've been using Maxthon (used to be MyIE2), and I am very satisfied.  It is a wrapper for IE, and it keeps instances of IE in a tabbed application.  I develop ASP.NET applications with Maxthon, and there is no difference because it uses the IE engine. 

Along the browser lines, if we (ASP.NET developers) developed pages using the XHTML standard with CSS, then we won't have so many cross-browser issues.  Standards for the web are well-established now, so we need to adhere to them so that browser choice doesn't matter. 

How many people still don't using a DOCTYPE in their pages?