A reactive computational notebook in a single HTML file.
JavaScript and Python in the same reactive document. No install, no server, no account — it runs entirely in your browser, and it works offline. Save it, email it, archive it: it's one file.
Inline CSS, HTML, and JS in a single self-contained .html. Nothing to install; nothing phones home.
Cells form a dependency graph. Change a value or drag a slider and everything downstream re-runs automatically.
Write JavaScript, or Python via adder — a real Python dialect that compiles to fast JS. Same reactive graph.
The network is an opt-in edge. It runs under a strict no-network policy, losing only explicitly network-named features.
Languages, cell types, and libraries plug in — geostatistics, GIS, plotting, dataframes, shaders, SQL, and more.
Releases are Ed25519-signed; the in-app updater verifies signatures before applying. Trust is checkable.
Real interpreters and compilers, running right in this page — each loads only when you hit Run. Edit the code and run it again.
› hit Run
Languages, science, and geoscience plug in as cell types and libraries — no package manager, no environment. A sample of what ships: