I use Jupyter Notebook quite a bit in a quantitative finance program I'm enrolled in for data modelling and visualization. Meanwhile, recently I've also been working more with C#, mostly in backend and full-stack development. At some point I started wondering if there's something similar to Jupyter in that world, something interactive where you can just run code in chunks.
Turns out there is: Polyglot Notebooks, built on top of .NET Interactive.
What Polyglot Notebooks is
Polyglot Notebooks is basically a Jupyter-style environment for the .NET ecosystem. You still get cells, stateful execution, and immediate output, but instead of being Python-centric, it's centered around C#.
The "polyglot" part comes from the fact that you can mix multiple languages in the same notebook, like C#, F#, PowerShell, and SQL. In fact, it feels more like a developer-focused scratchpad than a data science lab.
How they compare in practice
| Category | Jupyter Notebook | Polyglot Notebooks |
|---|---|---|
| Main focus | Data science | .NET development |
| Default languages | Python | C#, F#, PowerShell, SQL |
| Ecosystem strength | Very large (ML, data science, visualization) | Smaller, .NET-centric |
| UI experience | Browser-based (JupyterLab) | VS Code integrated |
| Best use case | Data exploration, ML, research | C# prototyping, scripting, dev experiments |
Jupyter feels like a proper data science workspace. Everything is optimized around Python's ecosystem, so working with data, models, and visualizations feels very natural.
Polyglot Notebooks feels more like a developer tool inside VS Code. It's useful for quickly testing C# code or mixing in SQL and scripting, but it doesn't really match the depth of Jupyter when it comes to data science workflows.
The unexpected ending
So I only just discovered it, got briefly excited about a neat little .NET "Jupyter moment," and by the time I finished reading the docs I learned that Polyglot Notebooks was deprecated in the VS Code ecosystem in March 2026. It feels like opening a shiny new toolbox only to find a sticky note inside saying "we've decided to sunset this entire toolbox, thanks for trying it though."
So I guess all I can say is: rest in peace, Polyglot Notebooks.