Despite the fact that ALICE relies on such an old codebase, the bot offers users a remarkably accurate conversational experience. Of course, no bot is perfect, especially one that’s old enough to legally drink in the U.S. if only it had a physical form. ALICE, like many contemporary bots, struggles with the nuances of some questions and returns a mixture of inadvertently postmodern answers and statements that suggest ALICE has greater self-awareness for which we might give the agent credit.
Founded by Pavel Durov, creator of Russia’s equivalent to Facebook, Telegram launched in 2013 as a lightweight messaging app to combine the speed of WhatsApp with the ephemerality of Snapchat along with claimed enhanced privacy and security through its use of the MTProto protocol (Telegram has offered a $200k prize to any developer who can crack MTProto’s security). Telegram has 100M MAUs, putting it in the second tier of messaging apps in terms of popularity.
Poor user experience. The bottom line: chatbots frustrate your customers if you are viewing them as a replacement for humans. Do not ever, ever try to pass of a chatbot as a human. If your chatbot suffers from any of the issues above, you’re probably creating a poor customer experience overall and an angry phone call to a poor unsuspecting call center rep.
Since 2016 when Facebook allows businesses to deliver automated customer support, e-commerce guidance, content and interactive experiences through chatbots, a large variety of chatbots for Facebook Messenger platform were developed. In 2016, Russia-based Tochka Bank launched the world's first Facebook bot for a range of financial services, in particularly including a possibility of making payments.  In July 2016, Barclays Africa also launched a Facebook chatbot, making it the first bank to do so in Africa. 
1. AI-based: these ones really rely on training and are fairly complicated to set up. You train the chatbot to understand specific topics and tell your users which topics your chatbot can engage with. AI chatbots require all sorts of fall back and intent training. For example, let’s say you built a doctor chatbot (off the top of my head because I am working on one at the moment), it would have to understand that “i have a headache” and “got a headache” and “my head hurts” are the same intent. The user is free to engage and the chatbot has to pick things up.
The process of building, testing and deploying chatbots can be done on cloud-based chatbot development platforms offered by cloud Platform as a Service (PaaS) providers such as Oracle Cloud Platform Yekaliva and IBM Watson. These cloud platforms provide Natural Language Processing, Artificial Intelligence and Mobile Backend as a Service for chatbot development.
But, as any human knows, no question or statement in a conversation really has a limited number of potential responses. There is an infinite number of ways to combine the finite number of words in a human language to say something. Real conversation requires creativity, spontaneity, and inference. Right now, those traits are still the realm of humans alone. There is still a gamut of work to finish in order to make bots as person-centric as Rogerian therapists, but bots and their creators are getting closer every day.
The classic historic early chatbots are ELIZA (1966) and PARRY (1972). More recent notable programs include A.L.I.C.E., Jabberwacky and D.U.D.E (Agence Nationale de la Recherche and CNRS 2006). While ELIZA and PARRY were used exclusively to simulate typed conversation, many chatbots now include functional features such as games and web searching abilities. In 1984, a book called The Policeman's Beard is Half Constructed was published, allegedly written by the chatbot Racter (though the program as released would not have been capable of doing so).