A lot has been going on with easyXDM over the past week, and I am proud to finally be able to release a version where all transport types, even the ones for IE6, deliver the same set of features.
From now on all the transports (and all the relying classes) supports

Reliability, ‘guaranteed’ delivery of messages
The new [...]

With the newest release, 1.7.4 (see the commits here), we have added two important features, fragmenting for the HashTransport, and queing for both the HashTransport and NameTransport

On thing that many are using easyXDM (and other cross-domain hacks) for, is to dynamically change the size of embedded iframes based on the contents size, so as to avoid the scrollbars.
To make it easier to do this using easyXDM, I have now published an example how how to do this here.
It really is easy, [...]

To accommodate older browsers that does not implement the postMessage interface, easyXDM is able to fall back to using the URI fragment trick, and until now this has meant that the provided hash.html file had to be uploaded to the local domain (the ‘calling’ domain).
This seems to be a dealbreaker for many as they are [...]

The newest version of easyXDM (v1.5.3) now includes two new classes, the easyXDM.WidgetManager, and easyXDM.Widget.
These make it extremely easy to make mashups based on the subscribe/publish architecture.

easyXDM is a javascript library that uses available techniques to provide a means of transporting messages and/or method calls between windows in different domains, in short, by-passing the same-origin policy and letting you call methods across the domain boundry.
This is perfect if you plan to provide a client-side API (e.g Facebook Connect) on your web [...]