not much happened today

Over the holiday weekend, key AI developments include the upcoming release of **Grok 4**, **Perplexity** teasing new projects, and community reactions to **Cursor** and **Dia**. Research highlights feature a paper on **Reinforcement Learning (RL)** improving generalization and reasoning across domains, contrasting with Supervised Fine-Tuning's forgetting issues. **Energy-Based Transformers (EBTs)** are proposed as a promising alternative to traditional transformers. **AI21 Labs** updated its **Jamba** model family with enhanced grounding and instruction following, maintaining a **256K** context window. **Baidu** open-sourced its massive **424 billion** parameter **Ernie 4.5** model, while **Kontext-dev** became the top trending model on **Hugging Face**. Advances in length generalization for recurrent models and the introduction of **2-simplicial attention** were noted. In biomedical AI, **Biomni**, powered by **Claude 4 Sonnet**, demonstrated superior accuracy and rare disease diagnosis capabilities. Additionally, the Python package manager `uv` received praise for improving Python installation workflows.