Many transformer-based models exist beyond ChatGPT, dating to the mid-2010s.
ChatGPT4 has dominated public discussion lately, but other well-known Large Language Models include GPT, BERT, Chinchilla, Gopher, Bloom, MT-NLG, PaLM, and LaMDA. All of these models are so-called transformers, initially introduced in 2017. Large Language Models have existed for several years, with their development and popularity growing rapidly since the mid-2010s. There were a few very successful early adopters, for example ultimate.ai, a company that automates every aspect of customer support.
— Large Language Models & AI In Healthcare · Forbes