The term chat bot (or sometimes just bot) can also be used in the meaning of an automatic chat responder program. The article How to Create a Chat Bot for Yahoo Messenger written by Chelsea Hoffman, explains how quick and easy it is to create a Chat bot responder containing unique and accurate responses to general phrases, words and questions that are used in Yahoo messenger.
AIML, Artificial Intelligence Markup Language developed by Richard Wallace, constitutes an open standard for creating your own chat bot. AIML file consists of row-type, database-style data combined with hierarchical XML data in each response. This video shows one of spreadsheet-style editors for AIML, Simple AIML Editor (SAE) developed by Adeena Mignogna. The SAE allows botmasters to manage large AIML sets and then zoom in on the templates to edit the responses.
The word bot, in Internet sense, is a short form of robot and originates from XX century. The modern use of the word bot 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 respectable 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.
However, the revelations didn’t stop there. The researchers also learned that the bots had become remarkably sophisticated negotiators in a short period of time, with one bot even attempting to mislead a researcher by demonstrating interest in a particular item so it could gain crucial negotiating leverage at a later stage by willingly “sacrificing” the item in which it had feigned interest, indicating a remarkable level of premeditation and strategic “thinking.”
2a : a computer program that performs automatic repetitive tasks : agent sense 5 Several shopping "bots" will track down prices for on-line merchandise from a variety of vendors.— Sam Vincent Meddis especially : one designed to perform a malicious action These bot programs churn away all day and night, prodding at millions of random IP addresses looking for holes to crawl through. — Jennifer Tanaka
Talking to a chatbot can be a lot of fun, and if you have the desire, dedication and skills to create, maintain and manage your own chatbot, you can do it. Whether you choose a fully stand-alone “virtual companion”, or take on the challenge of creating your own web-based chatbot, there are several options available to you, the prospective new botmaster, for creating a new chatbot. Nevertheless, first of all you have to choose between a stand-alone chatbot application, and a web-based chatbot.
The main challenge is in teaching a chatbot to understand the language of your customers. In every business, customers express themselves differently and each group of a target audience speaks its own way. The language is influenced by advertising campaigns on the market, the political situation in the country, releases of new services and products from Google, Apple and Pepsi among others. The way people speak depends on their city, mood, weather and moon phase. An important role in the communication of the business with customers may have the release of the film Star Wars, for example. That’s why training a chatbot to understand correctly everything the user types requires a lot of efforts.
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. 
Some bots communicate with other users of Internet-based services, via instant messaging (IM), Internet Relay Chat (IRC), or another web interface such as Facebook Bots and Twitterbots. These chatterbots may allow people to ask questions in plain English and then formulate a proper response. These bots can often handle many tasks, including reporting weather, zip-code information, sports scores, converting currency or other units, etc. Others are used for entertainment, such as SmarterChild on AOL Instant Messenger and MSN Messenger.
24/7 digital support. An instant and always accessible assistant is assumed by the more and more digital consumer of the new era. Unlike humans, chatbots once developed and installed don't have a limited workdays, holidays or weekends and are ready to attend queries at any hour of the day. It helps to the customer to avoid waiting of a company's agent to be available. Thus, the customer doesn't have to wait for the company executive to help them. This also lets companies keep an eye on the traffic during the non-working hours and reach out to them later.
[In] artificial intelligence ... machines are made to behave in wondrous ways, often sufficient to dazzle even the most experienced observer. But once a particular program is unmasked, once its inner workings are explained ... its magic crumbles away; it stands revealed as a mere collection of procedures ... The observer says to himself "I could have written that". With that thought he moves the program in question from the shelf marked "intelligent", to that reserved for curios ... The object of this paper is to cause just such a re-evaluation of the program about to be "explained". Few programs ever needed it more.