WASM-powered codespaces for Python notebooks on GitHub
Hi HN! Last year, we shared marimo [1], an open-source reactive notebook for Python with support for execution through WebAssembly [2]. We wanted to share something new: you can now run marimo and Jupyter notebooks directly from GitHub in a Wasm-powered, codespace-like environment. What makes this powerful is that we mount the GitHub repository's contents as a filesystem in the notebook, making it really easy to share notebooks with data. All you need to do is prepend 'marimo.app' to any Python notebook on GitHub. Some examples: - Jupyter Notebook:…
WASM-powered codespaces for Python notebooks on GitHub launched on January 14, 2025 with 204 votes, #194 of 6,142 launches that month and more than 95% of that year's launches. The site was still online in September 2026, 1 year on.
In plain words
Marimo is an open-source reactive Python notebook environment that runs directly in web browsers using WebAssembly. It allows users to view and execute both marimo and Jupyter notebooks from GitHub repositories without installation, with the repository's files accessible as a mounted filesystem. Users can access notebooks by prepending 'marimo.app' to any GitHub notebook URL, and Jupyter notebooks are automatically converted to marimo format. It is designed for Python developers and data scientists who want to share and run notebooks collaboratively online.
written from the facts on this page · September 2026
From the sources
Run marimo notebooks entirely in the browser with WebAssembly. No backend required. Share and embed interactive notebooks anywhere.
marimo lets you execute notebooks entirely in the browser , without a backend executing Python. marimo notebooks that run entirely in the browser are called WebAssembly notebooks, or WASM notebooks for short. Not all notebooks are compatible with WebAssembly. If you use coding agents like Claude Code, you can use our official skills to automatically check for WebAssembly compatibility of your notebooks. Read the molab docs to learn how to share WebAssembly previews of notebooks hosted on GitHub, and how to embed WebAssembly notebooks in other webpages such as documentation. WASM notebooks have three benefits compared to notebooks hosted using a traditional client-server model. WASM…from docs.marimo.io
In the maker’s words, at launch
Hi HN! Last year, we shared marimo [1], an open-source reactive notebook for Python with support for execution through WebAssembly [2]. We wanted to share something new: you can now run marimo and Jupyter notebooks directly from GitHub in a Wasm-powered, codespace-like environment. What makes this powerful is that we…
Does a similar job
all alternatives →
Marimo – an open-source reactive notebook for Python2024 · github.com · ▲448Hi HN! We’re excited to share marimo, an open-source reactive notebook for Python [1]. marimo aims to solve well-known problems with traditional notebooks [2]: marimo notebooks are reproducible (no hidden state), git-friendly (stored as Python files), executable as Python scripts, and deployable as web apps. GitHub repo: https://github.com/marimo-team/marimo In marimo, a notebook’s code, outputs, and program state are always consistent. Run a cell and marimo reacts by automatically running the cells that reference its declared variables. Delete a cell and marimo scrubs…
Marimo – open-source reactive Python notebook – running in WASM2024 · marimo.app · ▲102Hi HN! Last month, we shared marimo [1][2], an open-source reactive notebook for Python. For those who missed it, marimo notebooks are reproducible, stored as Python files, executable as Python scripts, and deployable as web apps. It’s now possible to run marimo notebooks entirely in the browser via WebAssembly (WASM). - A marimo tutorial as a WASM notebook: https://marimo.app/l/c7h6pz - Training a neural network with Karpathy’s micrograd: https://marimo.app/l/xpd4te - Visualizing attractors, as a read-only app:…
Molab, a cloud-hosted Marimo notebook workspace2025 · molab.marimo.io · ▲123We launched marimo [1], an open-source reactive Python notebook, last year on HackerNews. Today, the most popular recent feature request in Google Colab’s issue tracker asks for marimo support in Colab [2]. Rather than try to convince Google to replace their notebook with marimo, we decided to just build our own cloud-hosted notebook service instead. We're calling this molab (mo for marimo), and we're launching it today. You can try it at https://molab.marimo.io Some features: - Persistent storage - Link sharing (notebooks are public but undiscoverable, like secret GitHub Gists) -…
Marimo pair – Reactive Python notebooks as environments for agentsApr 2026 · github.com · ▲140Hi HN! We're excited to share marimo pair [1] [2], a toolkit that drops AI agents into a running marimo notebook [3] session. This lets agents use marimo as working memory and a reactive Python runtime, while also making it easy for humans and agents to collaborate on computational research and data work. GitHub repo: https://github.com/marimo-team/marimo-pair Demo: https://www.youtube.com/watch?v=6uaqtchDnoc marimo pair is implemented as an agent skill. Connect your agent of choice to a running notebook with: /marimo-pair pair with me on…
Marimo VS Code extension – Python notebooks built on LSP and uvNov 2025 · github.com · ▲65Hi HN! We're excited to release our VS Code/Cursor extension for marimo [1], an open-source, reactive Python notebook. This extension provides a native experience for working with marimo notebooks, a long-requested feature that we’ve worked hard to get right. An LSP-first architecture The core of our extension is a marimo notebook language server (marimo-lsp [2]). As far as we know, it’s the first notebook runtime to take this approach. The Language Server Protocol (LSP) [3] offers a small but important set of notebook-related capabilities that we use for document and kernel syncing;…
More dev tools this month
the category →
open-source IDE for thoughtful software design. Contribute to devdotfast/whiteboard development by creating an account on GitHub.
Dev tools · 28d ago · github.com
Contribute to reladraw/reladraw development by creating an account on GitHub.
Dev tools · 26d ago · github.com
OpenBot▲362Grok Bot alternative: free, local, open-source, multiplayer
Dev tools · 23d ago · openbot.run
Talanoa▲346Hi HN, I’m a fullstack developer, and honestly, I’ve lost count of how many side projects I’ve worked on over the years. But one idea kept coming back to me: a different kind of email client. It first came to me in 2014: “What if we could handle emails more like conversations?” Every year, I’d revisit this concept in my “Build Notes.” Ten years later, no one had built exactly what I had in mind — so I finally decided to do it myself. That’s how Talanoa was born. I wanted something focused on people, not timelines. I was tired of marking messages as unread just to remember to reply later, or…
Dev tools · 21d ago · talanoa.email
CoreSpeed▲332One MCP for everything your agents need: apps, memory, tools
Dev tools · 28d ago · corespeed.io
Source: Show HN post ↗ · launch text quoted in part
Launched alongside, January 2025
the whole month →
Hello! I'm Byran. I spent the past ~6 months engineering a laptop from scratch. It's fully open-source on GH at: https://github.com/Hello9999901/laptop
Dev tools · 2025 · byran.ee
- TITetris in a PDF▲1,289
I realized that the PDF engines of modern desktop browsers (PDFium and PDF.js) support JavaScript with enough I/O primitives to make a basic game like Tetris. It was a bit tricky to find a union of features that work in both engines, but in the end it turns out that showing/hiding annotation "fields" works well to make monochrome pixels, and keyboard input can be achieved by typing in a text input box. All in all it's quite janky but a nice reminder of how general purpose PDF scripting can be. The linked PDF is all ASCII so you can just open it in a text editor, or have a look at…
Life & fun · 2025 · th0mas.nl
21st.dev▲1,211I originally built this app to organize and reuse interesting React + Tailwind components I came across on Twitter, inspired by the shadcn/ui approach. Later, a friend started contributing their own components, and it got me thinking—this could grow into something bigger, like an NPM for design engineers to share and use components. Would love to hear your thoughts!
Dev tools · 2025 · 21st.dev
Create lifelike, personalized AI avatars from text prompts
AI · 2025 · jogg.ai
CSS library based on Counter Strike 1.6 UI.
Life & fun · 2025 · cs16.samke.me