A lot of people have requested that we added AJAX to certain parts of BlogEngine.NET, so we did.
The calendar widget to the right on this site is now ajaxified for a more smooth navigation between months. The postback reloaded the page every time you navigated to a new month and that was not very cool. The performance is actually pretty descent I think.
The comments have also been AJAX enabled, so that when you write a comment, there is no postback anymore. It makes sure that the browser supports AJAX before enabling it, so that it falls back to normal postback behaviour on old browsers. The invisible CAPTCHA still works when the browser doesn’t support AJAX. I have never seen ajaxified comments on other blogs, so it might be an exclusive feature of BlogEngine.NET.
Unfortunately I cannot share the bits with you because CodePlex is having problems, so there is no access to the source code. CodePlex say they will be back online within 96 hours. In the mean time you can try out the new calendar widget and the AJAX comments by posting one.