Laguna XS 2.1 is a 33B Mixture-of-Experts model with 3B activated parameters per token, tuned for agentic coding and long-horizon tasks on local machines. It outperforms XS.2 on SWE-bench Multilingual by 5.4 points, adds support for major runtimes, offers FP8/INT4/NVFP4 checkpoints, and runs with a permissive OpenMDW-1.1 license. You can access it via API, OpenRouter, or locally with quantized or DFlash-boosted builds.

This article breaks down the gap between your prompts (the map) and the real codebase (the territory) into four types of unknowns and shows how to uncover them. It offers concrete prompting patterns—blindspot passes, brainstorms, interviews, references, and implementation plans—to surface issues before, during, and after coding with Claude Fable 5.

Jane Street had long skipped full-on formal methods despite using advanced type systems, but the rise of agent-driven coding cut proof costs and widened access. They’re now forming a team to integrate formal verification into their OCaml toolchain, tweaking the language and tapping their experienced user base while collaborating with external proof ecosystems.

GPT-5.5 outperforms GPT-5.4 in real-world coding tasks, from debugging and large merge operations to interactive app development. It also serves as a research partner—critiquing manuscripts, proposing analyses, and generating reports on complex datasets—all while running at GPT-5.4 latency through integrated inference optimizations.