| 1. Claude Fable 5 (High) |
| 2. GPT 5.6 Sol (xHigh) |
| 3. Claude Opus 4.8 (Thinking) |
| 4. GPT 5.5 (xHigh) |
| 5. Claude Sonnet 5 (High) |
The BriefThinking Machines Lab, the startup founded by former OpenAI CTO Mira Murati, released its first model yesterday, and it is open-weights, meaning the actual model is free to download, run, and modify rather than locked behind a company's API. Inkling is a 975-billion-parameter mixture-of-experts model (only 41 billion fire on any given request, so it runs far cheaper than its size suggests), it handles text, images, and audio, and it lets you dial reasoning effort up or down per task. It ships under an Apache 2.0 license and was tuned for calibration, instruction-following, and resistance to censorship. It matters because it is the strongest US open-weights model yet, and it tests a real bet: that a model organizations can adapt for themselves beats the one-size-fits-all systems the biggest labs rent out.
Level UpThis is the week to get concrete about what open-weights actually buys you. Unlike ChatGPT or Claude, a model like Inkling can run on infrastructure you control, which is what makes it viable for data you cannot send to a third party. You do not need a GPU cluster to see it: Baseten and Databricks both put Inkling up for hosted trials the day it launched. Spend twenty minutes reading how it is deployed and running one prompt through it, and open-weights stops being a buzzword and becomes a real option you can weigh for your own work. Try it: a plain-English walkthrough of running Inkling