Once all the major features are complete and the API has been tested, the roadmap gives an idea of whats left to be done.
We don't have a list right now, but most of the API is stable as of 0.3.0. There should be no major changes at this point, though there will be lots of new additions.
As of 0.3.0, all the examples that ship with HTML_AJAX have been verified to work with
* Firefox 1.0+
* Internet Explorer 5.5+ (5.0 should work but it hasn't been tested)
Most things work with
* Safari 2+
* Opera 8.5+
It depends. With AJAX the answer is more in between. Control can be more centralized in a server-side component or as a mix of client-side and server-side controllers.
There are some use cases where an entire AJAX application can be written in a single page. Keep in mind if you choose this type of architecture that navigation and bookmarking should be considered.
Both methods are viable depending on what you are trying to accomplish. I tend to prefer spreading the control across the client and server.
No. XMLHttpRequest is only part of the Ajax equation. XMLHttpRequest is the technical component that makes the asynchronous server communication possible; Ajax is our name for the overall approach described in the article, which relies not only on XMLHttpRequest, but on CSS, DOM, and other technologies.