Siri voice assistant is available in portable electronic devices like the iPhone and the iPad.
Amazon which has developed the intelligent personal assistant Alexa baked into devices like the Echo smart speaker.
Alphabet subsidiary Google and its Google Now assistant available through Android and other Google software products.
Microsoft whose Cortana intelligent assistant is found in Microsoft products like the Xbox and its Windows operating systems.
IBMs Watson answering system. The intelligent personal assistants use natural language processing (NLP).