in Internet sense, c.2000, short for robot. Its modern use has curious affinities with earlier uses, e.g. "parasitical worm or maggot" (1520s), of unknown origin; and Australian-New Zealand slang "worthless, troublesome person" (World War I-era). The method of minting new slang by clipping the heads off words does not seem to be old or widespread in English. Examples (za from pizza, zels from pretzels, rents from parents) are American English student or teen slang and seem to date back no further than late 1960s.
Although Weizenbaum created his ELIZA thirty years before Internet became familiar to the general public, his creation is still alive and accessible to everyone. Watch the following video created by a youtube user IanProCastsCoUk, and see how the javascript version of Eliza emulates a Rogerian psychotherapist, responds on questions and leads simple conversations.
However, web based bots are not as easy to set up as a stand-alone chatbot application. Setting up a web-based chatbot requires at least minimal experience with HTML, JavaScript and Artificial Intelligence Markup Language (AIML). Additionally, any sort of “fancy” features, such as Text To Speech, or an animated avatar, would have to be created and integrated into your chatbot’s page, and certain features, such as voice recognition, are either unavailable, or are severely limited.

According to Richard Wallace, chatbots development faced three phases over the past 60 years. In the beginning, chatbot only simulated human-human conversations, using canned responses based on keywords, and it had almost no intelligence. Second phase of development was strictly associated with the expansion of Internet, thanks to which a chatbot was widely accessed and chatted with thousands of users. Then, the first commercial chatbot developers appeared. The third wave of chatbots development is combined with advanced technologies such as natural language processing, speech synthesis and real-time rendering videos. It comprises of chatbot appearing within web pages, instant messaging, and virtual worlds.
Bots for Messenger are for anyone who's trying to reach people on mobile - no matter how big or small your company or idea is, or what problem you're trying to solve. Whether you're building apps or experiences to share weather updates, confirm reservations at a hotel, or send receipts from a recent purchase, bots make it possible for you to be more personal, more proactive, and more streamlined in the way that you interact with people.
Messenger Bots are created using the new Messenger API that allows a bot to send and receive messages. The Messenger Bots are essentially chat bots that you can talk to from the Messenger app. The conversations will of course be different than those you have with your Facebook friends. These bots are meant to help you get information for example you can ask the CNN bot to tell you give you the current headline news and it will fetch them for you.