OpenAI
OpenAI is a US AI lab and the maker of the GPT and o1 model families. It is the largest commercial AI company by revenue and user base as of early 2026, with products including ChatGPT, the GPT API, and the o1/o3 reasoning model series.
Models (2026)
| Model | Notes |
|---|---|
| GPT-5 | Flagship; uses routing architecture — most queries sent to cheaper sub-models, reducing serving cost |
| GPT-5.2 Thinking | Updated version; long-context leader before and after Gemini competition; nathan-lambert’s information retrieval tool |
| o1 / o3 | Reasoning models with inference-time scaling (thinking tokens); commercialised RLVR |
| gpt-oss-120b | OpenAI’s first open-weight model since GPT-2; signals a shift toward open developer engagement |
Culture
nathan-lambert and sebastian-raschka describe OpenAI as chaotic but research-innovative — the lab that most consistently produces research surprises despite internal turbulence. The GPT-5 routing architecture (serving most queries through cheaper sub-models to reduce cost while maintaining quality on demanding tasks) is cited as an example of innovative production engineering.
Motivation for Open Release
Opening gpt-oss-120b allows OpenAI to offload inference compute costs to the developer community for lower-stakes tasks, while retaining the frontier proprietary API for premium use cases.