AI: Grok vs Opus 5.5; C vs JAX, SGLang

surprising they didn't use Rust :)

 Elon Just Called a Rival's AI a "Masterpiece" - YouTube @ Brighter with Herbert - YouTube

Competitive Status: Elon Musk recently admitted that xAI's Grok model is currently behind leading competitors, singling out Anthropic's Opus 5.5 as a "masterpiece." However, he expressed confidence that the upcoming Grok 5 could catch up or surpass it within 2 to 3 months.

Architecture Overhaul: xAI completely abandoned JAX and SGLang, rewriting its entire reinforcement learning and inference stack from scratch in C/C++ (with a minimal amount of C++).

Engineering Roots: Musk noted that the new AI training and inference stack draws directly from engineering solutions developed for Starlink, referencing low-level practices like writing custom headers and manually calculating time (including accounting for leap seconds).

jax-ml/jax: Composable transformations of Python+NumPy programs: differentiate, vectorize, JIT to GPU/TPU, and more  @GitHub

sgl-project/sglang: SGLang is a high-performance serving framework for large language models and multimodal models. @GtiHub