Originally Posted by: "Cliff" 
I have a difficult time working with/around Anthem, probably because I don't completely understand how to customize it in separate scripts.
 That's because the documentation sucks! 
That, and because Anthem is not an API like jQuery. 
Anthem tries to be drop-in replacements for the ASP.NET controls. I think it does that pretty well, but it suffers from a poor customization story (inherited from the poor customization story in the standard controls). 
Here's what Anthem wants to be: 
1. Take a WebForms page that is working well… 
<asp:GridView id="grid" runat="server">blah blah</asp:GridView>
<asp:Button id="button" runat="server">blah blah</asp:Button> 
2. Change "asp" to "anthem" and you have Ajax! 
<anthem:GridView id="grid" runat="server">blah blah</anthem:GridView>
<anthem:Button id="button" runat="server">blah blah</anthem:Button> 
That's it. That's all Anthem wants or tries to be. It will never do anything more. If this is what you need, then Anthem is a much better solution than MS Ajax, which tries to be this (but kind of fails because it does not support all the controls) and a little bit more (but not enough to be really useful). 
If you want to add drag-and-drop panels, or lazy loading, etc., then you have to use something additional. 
All of my BVC5 use a combination of Anthem and YUI. I like the simplicity of "ajaxifying" the controls (it literally takes 2 seconds) combined with the shiny stuff that I get from YUI.