How does data binding work in the AngularJS framework?

I haven't found technical details on their site. It's more or less clear how it works when data is propagated from view to model. But how does AngularJS track changes of model properties without setters and getters?

I found that there are JavaScript watchers that may do this work. But they are not supported in Internet Explorer 6 and Internet Explorer 7. So how does AngularJS know that I changed for example the following and reflected this change on a view?

myobject.myproperty="new value";