VM Times

Virtual machine as the name states is a software in which is possible to simulate some conditions that are software and hardware independent ( java virtual machine is an eg of this ).
AJAX is a combination of Javascript, CSS and XML in order to avoid that always that you make a selection at a page just a part of a web page is refreshed ( this happens at gmail http://www.gmail.com and here at Yahoo answers when you receive a best choice of answer )
native interface is something that it is native of language there is no need to access and configure other stuff.