Chatbots are fast becoming a go-to technology for digital transformations. Industries ranging from airlines to fast-food-chains and financial services are redefining services with help from chatbots, which automate service-related tasks by approximating human speech. And it's a win-win strategy, as chatbots free up employees to pursue higher-value functions and enable consumers to help themselves to relevant information, Q&A style. But not every company is using virtual digital assistants (VDAs) yet. For many, the technical implementation remains an important question.

Recently Sam Altman from Y Combinator announced a new online Startup School. The idea is to teach everyone how to start a startup and help them along the way with guidance from people who've started companies. Startup School will have guest speakers covering a wide variety of topics, including Alan Kay, Jan Koum (WhatsApp), Patrick Collison (Stripe), Steve Huffman (Reddit), Jason Lemkin (SaaStr), Harry Zhang (Lob), Dalton Caldwell (YC), Emmett Shear (Twitch), Adam D'Angelo (Quora), Alex Schultz (Facebook), Tracy Young (PlanGrid), Michael Seibel (YC), Kirsty Nathoo (YC), Vinod Khosla (Khosla Ventures), Ali Rowghani (YC), Jess Lee (Sequoia), and Aaron Harris (YC). Our company ChatBottle was one of a few chatbot startups enrolled in the course. Each group has its own mentor, usually a founder of a well-known company or a YC alumni.

A few months ago we wrote about The Top 10 Artificial Intelligence Startups in China and Mobvoi made that list. Founded in 2014, Massachusetts startup Semantic Machines has taken in $12.38 million in a single round of funding. This startup is developing a new platform that is language-independent by shifting conversation from understanding commands to understanding conversations (even tonal languages like Mandarin). Automat is making it easier for anyone to build a bot that uses artificial intelligence and human expertise to enable "business conversations at scale".

Dr. Yoshua Bengio, one of the key researchers credited with establishing the field of deep learning, announced today that he will serve as a strategy adviser for legal tech company Botler AI, a Montreal-based startup that runs a free chatbot to assist users as they navigate the legal procedures required for immigration. "I knew this was an idea that we needed to take to the next level," Bengio said in today's press release. "I want AI to be developed towards positive social impact and this is one place where beneficial AI must happen." The techniques pioneered by Bengio and others have led to breakthroughs in natural language comprehension and translation, abilities that are critical to this kind of chatbot. "Deep Learning could help provide affordable or even free legal services to people who might otherwise not be able to have access," he said.

The "marketing conversation" will become a human-machine conversation. That the essence of marketing is a "conversation" between a business (or any "brand") and its customers and potential customers has been a marketing tenet (and cliché) for a long time. While that conversation has been conducted over the last twenty years increasingly through a computer screen with the help of a keyboard, it is now transforming into human-machine conversation. "The conversational UI," says Shah, "is going to be an even bigger leap in software than we had with the shift to Web-based software. We are all re-thinking now how to build products."

Chatbots are programs that mimic conversation with people using artificial intelligence. With recent advances in AI these have become much more accurate, especially when focused on a specific domain. Combine these advances with the consumer trend towards messaging -- people are now spending more time in messaging apps than in social media -- and it seems we might be about to enter the age of the chatbot. We decided to take a closer look at the top emerging chatbot start-ups in text chat, across a range of industries, and pick out the most promising. You can find out more about the 25 companies below, or discover more chatbot startups on our search engine.