TRL
Hugging Face's Transformer Reinforcement Learning library — the standard toolkit for RLHF, DPO, GRPO, and reward modeling. DeepSeek's GRPO technique that sparked the reasoning model wave was popularized through TRL. Integrates seamlessly with the full Hugging Face ecosystem.
HuggingFace
The central hub for open-source ML models, datasets, and spaces. Offers Inference API, Inference Endpoints, and the Transformers library for running models.