marimo
The notebook that fixes notebooks
What it is
A reactive Python notebook stored as pure .py files. Cells form a dataflow graph, so a change automatically re-runs everything that depends on it — no hidden state. Notebooks run as scripts, deploy as apps, query with SQL, and version cleanly in git, with an AI-native editor built in.
Why it's interesting
A modern, reproducible, fully Apache-licensed answer to Jupyter's oldest pains: hidden state and unversionable JSON. The reactive model and pure-Python storage fix both, and the AI features make it a strong notebook pick for 2026.
Use cases
- Reproducible data analysis
- Interactive data apps and dashboards
- SQL-plus-Python exploration and teaching
Who it's for
Data scientists, analysts, ML engineers, educators
Setup
Easy. Python, pip install marimo (or marimo[recommended] for SQL and AI); a modern browser
Limitations & cautions
The reactive model differs from classic Jupyter and takes adjustment; expensive cells may need explicit lazy configuration; AI features depend on external providers.
Editorial takeaway
Everyone complains about notebook reproducibility and then opens Jupyter anyway. This is the one worth switching for.