Show HN: Newton's Orchard – Browser-based space/gravity playground https://ift.tt/8TzdN3v

Show HN: Newton's Orchard – Browser-based space/gravity playground Hi HN! My son spent a lot of time in 5th grade playing with the 2-dimensional PhET gravity/space sims[1]. His STEM class uses it, and he was playing with it at home, and has been looking for more. I found several space sims/playgrounds online, including NASA's Eyes on the Solar System[2], but nothing that seemed to offer a real progression from what he was getting out of the PhET sims, so I built Newton's Orchard over the summer for him. https://ift.tt/rglLDpx The source is also published at https://ift.tt/81gsXuB It features deterministic time scrubbing, all bodies are editable, different preset systems and experiments, missions to complete (complete 3 to unlock the blackhole object type and mission), and a gallery for user submissions. I would very much appreciate feedback from HN - particularly from the lens of making it engaging and illuminating for students, and anyone that would like to just get a feel for how gravity works. Thank you! [1] https://ift.tt/pbqKZla... [2] https://ift.tt/YyD0z9T https://ift.tt/rglLDpx September 1, 2026 at 11:43PM

Show HN: Semantic Overlays – an NX bit for LLM prompt injection (live demo) https://ift.tt/Qm8YsK4

Show HN: Semantic Overlays – an NX bit for LLM prompt injection (live demo) I've built a new method for steering LLMs called Semantic Overlays, small trained adapters on a frozen model which change how its perceives a piece of its context. The most readily applicable usage is to mitigate prompt injection, and it lets us take a very-injectable Qwen-3.5-9B to SOTA scores on all the prompt injection benchmarks I could find. (They are only blackbox attacks, but I did NOT train on anything like them — whitebox attacks are out of scope for this paper) I'm excited for you to play with the tech — see if YOU can break it! (let me know if you can) Paper at https://ift.tt/Ah9erJX if you want to read more about it, code at https://ift.tt/a9wvnZR , adapters at https://ift.tt/X7VWDKl... Also https://ift.tt/vHP63nw if you wanna watch a little video I made! https://semantic-overlays.vercel.app/ September 2, 2026 at 12:40AM

Show HN: Running 104GB Qwen3.8-Flash-Next on 48GB Mac with at ~12 tok/s https://ift.tt/M4IhHVX

Show HN: Running 104GB Qwen3.8-Flash-Next on 48GB Mac with at ~12 tok/s I built slotstream, a way to run Qwen3.8-Flash-Next 4-bit on a low-memory mac starting from 16GB, a 125B parameter model that would need 100GB+ memory/RAM, thanks to expert-offloading/ssd-streaming. Easy to install/update, and mac-native using MLX and Swift. It ships with auto-mode, which makes a good tradeoff between memory usage and speed. I'll be implementing and porting the MTP module for speculative decoding next https://ift.tt/Nl6hi4y September 1, 2026 at 11:42PM

Show HN: Keel - A conductor, not an agent loop https://ift.tt/at5u3wA

Show HN: Keel - A conductor, not an agent loop https://daneb.github.io/keel/ September 1, 2026 at 03:22AM

Show HN: Guess the AI model from its web design https://ift.tt/DZc4Mvr

Show HN: Guess the AI model from its web design https://ift.tt/wTsmoOY September 1, 2026 at 02:40AM

Show HN: Corporate Mind Games – logic puzzles with a sarcastic corporate theme https://ift.tt/3uLJktU

Show HN: Corporate Mind Games – logic puzzles with a sarcastic corporate theme I have always enjoyed building and playing puzzles. I am a regular user of NYT Games and LinkedIn Games. I thought it would be fun to create some corporate-themed puzzles as a silly alternative to LinkedIn Games. So, I built Corporate Mind Games. The games are intended to be a little bit sassy and sarcastic, but I hope they are enjoyable and challenging. I was planning to post this on HN last week. However, many years ago, I made a game called Don't Wordle, which unexpectedly appeared on the front page last week. I ended up getting distracted by that, and I also figured it was more appropriate to post this game on HN on a Monday morning given the theme. So here we are. https://ift.tt/iCtb39h August 31, 2026 at 11:08PM

Show HN: BentoPDF, Hyper Compress and Kura https://ift.tt/daKmRbU

Show HN: BentoPDF, Hyper Compress and Kura Hello. I developed an open source tool called BentoPDF. Its an open source PDF toolkit that runs in your browser. With the latest update, you can actually edit existing pdf text, images and objects right in your browser. Live Website: https://ift.tt/uTrHJIU Repository: https://ift.tt/v2hq16U Along with the latest update I would like to share with you Hyper Compress. Its a high fidelity, content preserving compression engine that preserves PDF conformance and surpasses all the other open source PDF compression tools. It runs everywhere: CLI, Node SDK, C API, self hosted service, and also in browser via WebAssembly. Live Website: https://ift.tt/xCzmZcw Repository and benchmarks: https://ift.tt/sCQmIKc Kura is a PDF standards, conversion and preflight engine. It supports: - All 11 PDF/A conformance levels: PDF/A-1a, PDF/A-1b, PDF/A-2a, PDF/A-2b, PDF/A-2u, PDF/A-3a, PDF/A-3b, PDF/A-3u, PDF/A-4, PDF/A-4e and PDF/A-4f - Accessibility: PDF/UA-1 and PDF/UA-2 - Print production: PDF/X-1a, PDF/X-3, PDF/X-4, PDF/X-4p, PDF/X-5g, PDF/X-5n and PDF/X-5pg - Engineering and variable data printing: PDF/E-1 and PDF/VT - E-invoices: Factur-X, ZUGFeRD, XRechnung and Order-X - 396 bundled print-preflight profiles It has been tested against several standards suites, including the veraPDF corpus, Isartor, BFO, Ghent Output Suite 5.0, the PDF/UA Reference Suite and Cal Poly's PDF/VT suite. Across 30,677 PDF conversions it had zero crashes and zero timeouts, with a 0.05 second median conversion time. Like Hyper, it ships as a CLI, C library, npm package, Docker image and WebAssembly build. Live Website: https://ift.tt/o4vhszj Repository and benchmarks: https://ift.tt/czxwSDV Both Kura and Hyper Compress are running the WASM build so none of your PDF is uploaded and everything runs in your browserr If possible I would like you guys to try them out and give me feedback on how it worked for you. Thank you. https://ift.tt/uTrHJIU August 30, 2026 at 10:57PM

Show HN: 3D Embodiment of your Git repo https://ift.tt/y4Zjker

Show HN: 3D Embodiment of your Git repo https://ift.tt/uRt2Nvn August 30, 2026 at 12:49AM

Show HN: Flint – A minimal C/C++ package manager and build tool written in C https://ift.tt/GJxByr4

Show HN: Flint – A minimal C/C++ package manager and build tool written in C https://ift.tt/CvugihQ August 30, 2026 at 12:44AM

Show HN: Free lifetime pro access to a crunchbase alternative https://ift.tt/ONLvzwu

Show HN: Free lifetime pro access to a crunchbase alternative A month ago we launched on HackerNews and reached the front page! As a thank you we are now offering free lifetime pro subscriptions to the HN community! https://ift.tt/tEVuKzP August 28, 2026 at 11:07PM

Show HN: Get agents to do what I want with code documentation https://ift.tt/Ab9aYXl

Show HN: Get agents to do what I want with code documentation https://ift.tt/eCzsbI7 August 28, 2026 at 10:20PM

Show HN: I built a site to share and find Claude Code passes https://ift.tt/FUtMhbm

Show HN: I built a site to share and find Claude Code passes This is an exchange site for people with paid Claude accounts who want to get free credits for sharing their passes. When someone redeems your Claude Code coupon, Anthropic credits you $10 in usage. I’ve already added mine. If you have a paid Claude account, run "/passes", get your coupons, and add them to the site too. https://ift.tt/pIDyXPT August 27, 2026 at 10:43PM

Show HN: A robot football league where frontier AI models manage the clubs https://ift.tt/w9W0UTb

Show HN: A robot football league where frontier AI models manage the clubs https://rfl.football August 26, 2026 at 08:53PM