Open Antimatter
Open Source Landing Pages, Sites, and Apps for the AI age
What it does
A curated collection of free, open-source software built by Antimatter AI — landing page templates, full-stack apps, AI tools, and more. Production-ready and free to use, fork, and deploy. Pro templates are paid and delivered by email after checkout.
Does the same job
all alternatives →- OSOpen-Source AI Playground2023 · chathub.gg · ▲47
- OSOpen-source playground to red-team AI agents with exploits publishedMar 2026 · github.com · ▲30
We build runtime security for AI agents. The playground started as an internal tool that we used to test our own guardrails. But we kept finding the same types of vulnerabilities because we think about attacks a certain way. At some point you need people who don't think like you. So we open-sourced it. Each challenge is a live agent with real tools and a published system prompt. Whenever a challenge is over, the full winning conversation transcript and guardrail logs get documented publicly. Building the general-purpose agent itself was probably the most fun part. Getting it to reliably use…
- OSOpen-Source AI Templates to help you build your next product2024 · metaschool.so · ▲12
Today, we're launching AI Templates at Metaschool: a curated collection of open-source, in-demand AI product templates. We've spent months identifying the hottest product ideas and the best ways to build them using AI. Everything is 100% open source—fork, clone, and start building immediately. Our hope is that these templates will help you spin-off your own product and start your business without a big team or large investment. We're starting with 17+ templates, which can spawn around 1700 unique products. For example - 1. Customer Service GPT: Provide a website link and instantly spin up a…
OpenSidekickJul 2026 · opensidekick.app · ▲8Open-source AI browser agent that runs any model you choose
More ai this month
the category →
I trained a 125M-parameter transformer to autocomplete piano performances in real time (~108 notes/sec on an iPhone 15). The idea is basically GitHub Copilot or Tabnine, except instead of prompting it with code, you prompt it by playing a few notes on a MIDI piano. The model then continues what you played, entirely on-device. The app is free if anyone wants to try it. Happy to answer questions about the model, training, Core ML, or the many things that didn't work.
AI · 17d ago · simedw.com
Astute▲585Automate your B2B brand going viral, with new media creators
AI · 18d ago · company-app.joinastute.com
Hey HN, Henry from Cactus here! We previously released Cactus Needle, a 14MB agentic LLM for tool call, device use, and structured extraction for phones, wearables, smart homes, small robots and microcontrollers. We got really great feedback here, and have now incorporated the suggestions to release Needle 2. The whole model is a single 14MB binary that runs a full session in 28MB of RAM; 45m parameters at 2bit compression. Needle hits 500 tokens/sec decode speed on a Raspberry Pi 5, sits between 400-1,500 tokens/sec on VR devices like Meta Quest 3S and Apple Vision Pro, and ranges…
AI · 27d ago · cactuscompute.com
Launched alongside, April 2026
the whole month →
- AG
Thought the resources for GPU arch were lacking, so here we are
Life & fun · Apr 2026 · jaso1024.com
- IB
Built a ~9M param LLM from scratch to understand how they actually work. Vanilla transformer, 60K synthetic conversations, ~130 lines of PyTorch. Trains in 5 min on a free Colab T4. The fish thinks the meaning of life is food. Fork it and swap the personality for your own character.
AI · Apr 2026 · github.com
- BC
Life & fun · Apr 2026 · sam-burns.com
- IB
With social media and now AI, its important to keep the indie web alive. There are many people who write frequently. Blogosphere tries to highlight them by fetching the recent posts from personal blogs across many categories. There are two versions: Minimal (HN-inspired, fast, static): https://text.blogosphere.app/ Non-minimal: https://blogosphere.app/ If you don't find your blog (or your favorite ones), please add them. I will review and approve it.
AI · Apr 2026 · text.blogosphere.app