I found this article pretty informative
http://ajax.sys-con.com/read/166503.htm

It describes the different layers of AJAX APIs that are available
(from simple wrapping of transportation protocol to full-on widget
libaries that are integrated into IDEs).

This seems relevant to our conversations last month, where David
Mendals (Macromedia/Adobe) talked about "comparing apples to
oranges", and Jep Castelein (from backbase) contrasted "mature AJAX
toolkits" with "custom ajax projects".

The article is by Kevin Hackman, from General Interface/TIBCO. He
basically says that current AJAX toolkits/libraries fall into one of
four groups (described in order of ascending complexity / power / value).
1)Communication libraries
2)User Interface Components
3)Rich Internet Application frameworks
4)RIA Frameworks with robust visual tooling

I'd quibble with (1) (in my experience, low-level libraries like
Prototype also abstract away differences between how different
browsers implement innerHtml, do event handling, position elements on
the screen, and much more). Maybe a better way to say 1 would be
"provide an API wrapping of existing browser functionality". Other
than that it's a nice model.

Recent events at the Apache
http://www.jonathanboutelle.com/mt/archives/2005/12/tooling_comes_t.html
http://www.nabble.com/AJAX-Toolkit-Framework-Proposal-t778101.html
might bring Zimbra/Rico from (3) status to (4) status. (Up till now,
everything in (4) is either proprietary or generates Flash rather
than JavaScript).

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Jon Boutelle
Principal, Uzanto Consulting
Mountain View, CA

Office Phone:650-564-0000
skype id: jboutelle
www.uzanto.com
www.jonathanboutelle.com
www.themindcanvas.com
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