Major Foundation Model Providers OpenAI (USA, founded 2015) is the pioneer of today’s LLM boom. Its flagship GPT (Generative Pre-trained Transformer) series includes GPT-3 (2020, 175B parameters) and GPT-4 (2023), which power ChatGPT and Codex (coding assistant). GPT-4 and now GPT-4 Turbo support very large context windows (up to 128K tokens, ~300 pages of text). […]