A developer's guide to chatbots

The very first chatbot, ELIZA, was developed 50 years ago at the Massachusetts Institute of Technology. It simulated a Rogerian psychotherapist, someone who just repeats the human user's words back to the human; it is not very good. In the following decades, chatbots were mostly of academic interest. But in recent years, smartphone-based chatbots have gained wide interest from the industry with high profile products such as the Apple Siri, Amazon Echo, and China's WeChat. In 2016, chatbots are one of the hottest trends in technology.