Intelligent virtual assistants (IVAs) have been transformed by the use of machine learning (ML) to provide more accurate machine to human conversation, whether by voice or text, than other techniques alone. Vendors with expertise in linguistics and semantics have been able to combine the best features of such technologies with the recent breakthroughs in deep learning neural networks and achieve superior performance. Today, all the leading IVA players have embraced ML and this field is an excellent showcase for how ML has moved from the research lab into real world applications.