Anthropic

Anthropic overall model is called Claude after Claude Shannon from his work on information theory.

Claude has several classes of LLMs (full list) that can be accessed through a dedicated API.

1. Fable 5.1
2. Opus 5.5
3. Sonnet 5.5
4. Haiku 5.5

OpenAI

OpenAi overall model is called GPT from the technology that builds the model -generative pre-trained transformer (I think GPTT was too complicated).

OpenAI has loads of models (full list). These the are the following publicly available models

1. GPT-6 Astra
2. GPT-6.1 Sol
3. GPT-6 Luna

The other models are based on more specific use cases such as image or audio generation. GPT 5.6 models are still available.

Google

Google was first and then late to the LLMs have created the first transformer architecture in 2017. It gets a little complicated with Google as they are partnered with Google.

The main one is Google Gemini (formerly Bard) but there are others for specific jobs.

Veo is a video generation system – https://aistudio.google.com/models/veo

Vertex used to build AI models but is now part of Gemini Enterprise Agent Platform.

Meta

Meta doesn’t have a set of models (from what we can find). You access the meta.ai with a Facebook (meta) account

Grok

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