Welcome to the Era of ChatGPT et al.

The emergence of Large Language Models (LLMs) in combination with easy-to-use interfaces such as ChatGPT, Bing Chat, and Google's Bard represent both a Herculean task and a sublime opportunity for Business and Information Systems Engineering.The technology and its applications already have considerable impact in many domains directly related to the design, operation, and application of information systems.In this editorial, we seek to explore this new reality as researchers, practitioners, and legislators will -in some form or another -have to deal with it.Our goal is to provide insights and encourage research in this new, exciting, and rapidly developing field. From Foundational Technology towards Killer ApplicationChatGPT emerged as the hottest topic on the Internet at the end of 2022 and established itself as a ''cultural sensation'' (Thorp 2023).This spontaneous hype can be seen as the latest pinnacle of the steady development of AI-powered chatbots, language-related services (e.g., for translation or content generation), and special research applications (e.g., for protein design; Madani et al. 2023) over the last couple of years.These systems instantiate sophisticated natural language processing (NLP) techniques within massive computational infrastructures to communicate fluently with humans.Today, conversational AI relies on neural transformer models (Uszkoreit 2017).These models are excellent at processing longer sequences of data-like text-by using self-attention processes that enable the model to focus on different areas of the input.A significant advancement in NLP is the emergence of LLMs, which are constructed using the transformer architecture.These models combine large-scale architectures with huge amounts of textual training data.This scaling up has allowed LLMs to understand and generate text at a level