Show HN: JSynth – Visual Programming Editor for Julia https://ift.tt/EjLp8cl

Show HN: JSynth – Visual Programming Editor for Julia https://ift.tt/uPwrlYz October 18, 2026 at 03:55AM

Show HN: 500 clocks in one 6.3 MB HTML file by Opus 5.5 https://ift.tt/xvh91aK

Show HN: 500 clocks in one 6.3 MB HTML file by Opus 5.5 Lately I've been testing frontier models by having them create self-contained web pages that display clocks--sort of my personal version of Simon Willison’s pelican-on-a-bicycle metric. I have been particularly impressed by the variety, interest, and quality of the clocks created by Claude Opus 5.5. Over the course of several sessions in the Claude chat interface, I had it build a total of 500 clocks. Claude’s summary of the prompting process and page design is here: https://ift.tt/TDOY7Kg https://ift.tt/PWyuNYK October 18, 2026 at 01:04AM

Show HN: Cosplay as a tech lead, using gVisor to sandbox agents https://ift.tt/Vv0bCI8

Show HN: Cosplay as a tech lead, using gVisor to sandbox agents Hi everyone, This started as an exploration into harnesses and locally hostable LLMs (the kind that uses less power than a small electric heater), and I used it as an opportunity to retool. I've tried popular ones like Cline, Claude Code, and Pi, but wanted a different UX and integrated sandboxes. The solution that I've landed on is a responsive web interface where I can quickly drive progress. It feels like a microcosm of my day job: define and delegate tasks, organize using kanban, then review deliverables. And it also feels like the time I used to spend coding is now spent in code review with the agent, so I tried to optimize the UX to make review feel nicer. One of my (maybe a bit niche) benchmark use-cases is how pleasant it is to make progress on hobby software projects while also out on a hike. This meant specifying low bandwidth usage and offline mode. Now I can jot down an idea, start the task, and at some point down the trail: get a notification* that either clarification is needed, a decision needs to be made, or the code is ready for review. I've been having a good time with this. To build MIKE, I exclusively used locally hostable LLMs (from Google, Meta, Qwen, Poolside, and DeepSeek) hosted with llama.cpp on my machines at home (Strix Halo and a 5090) to "compile" the code. The experience has gotten substantially better ever since DeepSeek’s release in July. Side note: I have a soft spot for llama.cpp since it was one of the first that made it possible to run this new tech at home, and its maintainers accepted a tiny improvement I made to error reporting. Oh the joys of having a PR get approved. I plan on maintaining this, at least until similar features are supported by better tools. Until then, hope you find this useful! 5 minute demo: https://youtu.be/jexzLkZ50FU p.s. I didn't mention details about the sandbox earlier since most people seem to find this a bit boring. It was one of my critical requirements, and I opted to use an existing battle-tested sandbox. I'm not an expert on how the Linux kernel works, but seeing all the VM escape exploits recently is a bit scary, and I liked gVisor’s approach to the problem. I'm also using Git worktrees to provision the agent’s workspace, as well as a read-only repository mount to provide relevant context when the agent looks for it. *off by default https://ift.tt/NotLnUl October 17, 2026 at 10:49PM

Show HN: Calcy – unit-aware, uncertainty-propagating math https://ift.tt/sSLukH0

Show HN: Calcy – unit-aware, uncertainty-propagating math Offline-first notepad calculator: unit-aware math, uncertainty propagation, and rate reasoning. https://ift.tt/79abzJm October 17, 2026 at 03:40AM

Show HN: Llmspeed – feel how fast a local LLM runs before you buy the hardware https://ift.tt/YAwxb7J

Show HN: Llmspeed – feel how fast a local LLM runs before you buy the hardware https://llmspeed.dev/ October 17, 2026 at 01:36AM

Show HN: Twain, a diff viewer like Meld, but for the age of AI https://ift.tt/Z59iCHI

Show HN: Twain, a diff viewer like Meld, but for the age of AI I love Meld, I've been using it for a while now, it's amazing how many diff viewers exist these days and how they are all awful compared to Meld. But Meld was missing some features that I thought were worth having: - all files from a Git diff shown in the same view, sequentially + a file tree on the side. - show either the full files or only the parts that changed. - tree-sitter-based syntax highlighting. - the ability to comment on sets of changes and lines, and AIs can read these comments. - the ability to search through the entire set of modified files. Twain is in Rust and based on GTK4. https://ift.tt/HRFLr71 October 16, 2026 at 11:03PM

Show HN: Kitaphone – Call mobile phones and landlines directly from the browser https://ift.tt/gAI5Upx

Show HN: Kitaphone – Call mobile phones and landlines directly from the browser Hi HN Folks, I have been building Kitaphone a web app that lets you call regular mobile and landline numbers directly from your browser. The idea is simple, there are still plenty of situations where apps like WhatsApp, facetime and other internet calling apps aren't an option. For example, when you are abroad and need to call your bank, an airline, or a government office or your son/daughter's school. I wanted to make those calls possible without requiring users to install another app or buy a sim card or even commit to a monthly subscription. I built Kitaphone using Next.js and Twilio, One of the more interesting challenges has been making browser based calling reliable, especially when it comes to dealing with microphone permissions, sending keypad inputs to automated phone systems, and preventing abuse of free calling credits. The product is live and supports international calls to regular phone numbers, users currently need an account to make calls partly because each call has a real telecom cost. I am still improving it and learning from the people using it by receiving feedback. Fun fact: "kita" means our in Bahasa Malaysia, since I am based in this beautiful country and their people are so warm and welcoming I was truly inspired by this place and decided to name it our phone. Interested to know or receive feedback from HN folks who worked with WebRTC or VoiP in the past. https://kitaphone.com October 16, 2026 at 12:30AM