"Notebooks" like Jupyter, or Github Spaces and VS Code for the web, where a lot of the processing runs on a remote server, and the result is displayed in the browser.
Jupyter runs natively in the browser now with JupyterLite: https://github.com/jupyterlite/jupyterlite It can use a native browser JS kernel, or some languages that have been converted to run in the browser with WASM (including a full python environment called pyodide). Nothing is run on a server.
VS Code also runs natively in the browser now: https://code.visualstudio.com/blogs/2021/10/20/vscode-dev This uses a Chrome only (for now) filesystem access API to give the browser access to your native files--you can edit them entirely in the browser with nothing happening on a server.
