kai
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We are offering grants of $100,000 + Tinker credits to researchers advancing the field of human-AI interactivity. Submit your proposals by June 19th! thinkingmachines.ai/news/interacti…







Today, we are thrilled to officially launch RadixArk with $100M in Seed funding at a $400M valuation. The round was led by @Accel and co-led by @sparkcapital. RadixArk exists to make frontier AI infrastructure open and accessible to everyone. Today, the systems behind the most capable AI models are concentrated in a small number of companies. As a result, most AI teams are forced to rebuild training and inference stacks from scratch, duplicating the same infrastructure work instead of focusing on new models, products, and ideas. RadixArk was founded to change that. We are building an AI platform that makes it easier for teams to train and serve the best models at scale. RadixArk comes from the open-source community. We started with SGLang, where many of us are core developers and maintainers, and expanded our work to Miles for large-scale RL and post-training. We will continue contributing to both projects and working with the community to make them the strongest open-source infrastructure foundations for frontier AI. We would like to thank our long-term partners, contributors, and the broader SGLang community for believing in this mission. We're also grateful to @Accel and @sparkcapital, NVentures (Venture capital arm of @nvidia), Salience Capital, A&E Investment, @HOFCapital, @walden_catalyst, @AMD, LDVP, WTT Fubon Family, @MediaTek, Vocal Ventures, @Sky9Capital and our angel investors @ibab, @LipBuTan1, Hock Tan, @johnschulman2, @soumithchintala, @lilianweng, @oliveur, @Thom_Wolf, @LiamFedus, @robertnishihara, @ericzelikman, @OfficialLoganK, and @multiply_matrix among others. Thanks for the exclusive interview with @MeghanBobrowsky at @WSJ about our vision.



LIVE TRIAL UPDATE: OpenAI's counsel asked Musk whether xAI has ever "distilled" technology from OpenAI. Musk: "Generally AI companies distill other AI companies." "Is that a yes?" Savitt asked. Musk: "Partly."






People are misreading the SpaceX/Cursor deal as an M&A story. It’s actually a bet on what the real bottleneck in frontier coding models is. xAI has struggled to close the gap with Claude Code and Codex. Cursor sits on the best corpus of developer traces in the world. The deal lets Cursor train Composer on Colossus while xAI runs the same recipe on Grok. Both sides find out, at the same time, whether Cursor's data is actually the difference. The option structure reflects that uncertainty. If the training work ports over, SpaceX buys Cursor and owns the pipeline. If it doesn’t, they pay $10B for the experiment and walk. Either outcome, Grok ends up stronger than it would have been, and xAI gets an answer to a question it couldn’t answer internally. The part worth holding onto: a pre-IPO company just priced a live experiment to figure out whether real developer traces are the scarce input in coding agents. $10B is what they’re paying to run it. $60B is what the answer is worth if it comes back yes.






