Companies that train and release their own large language models and foundation models. These organizations invest in large-scale model training, publish research, and offer API access to their proprietary models.
22 tools compared · Layer 4 · Updated March 27, 2026
Ranked by community traction, recent activity, and popularity.
OpenAI
GPT-4o and GPT-4 Turbo frontier models
OpenAI is the creator of ChatGPT and the GPT series of large language models, having pioneered the commercial LLM API market. Founded in December 2015 by Sam Altman, Elon Musk, Greg Brockman, Ilya Sutskever, and others as a non-profit, it transitioned to a capped-profit model in 2019 and is currently restructuring as a for-profit public benefit corporation.
Anthropic
Claude 4 and Claude 3.5 Sonnet models
Anthropic is an AI safety and research company that builds the Claude family of large language models. Founded in 2021 by Dario Amodei (CEO) and Daniela Amodei (President), along with five other former OpenAI employees, the company is structured as a Public Benefit Corporation with a Long-Term Benefit Trust to prioritize societal benefit.
Voyage AI (MongoDB)
Text & multimodal embeddings
Cohere
Command R+ for RAG applications
Microsoft
Small language models
xAI
Grok models with real-time data access
DeepSeek
DeepSeek-V3 and DeepSeek-R1 models
Databricks (DBRX)
Moonshot AI
Black Forest Labs
Image generation
Alibaba Qwen
Qwen2 open-source model series
Snowflake
Arctic models
Stability AI
Stable Diffusion image generation
Reka
01.AI
Zhipu AI
Guide Labs
Inherently interpretable LLM architecture
Cascade
Model distillation
Luel
Natural language to training data
Respan lets you trace LLM and agent calls across any model or framework, A/B test prompts on production traffic, and route requests across 1,000+ models through one gateway.
Try Respan free