JupyterLite vs NextLeet Playground

JupyterLite is a free, open-source JupyterLab distribution that runs entirely in a browser. It provides JupyterLab and Jupyter Notebook interfaces, plus a minimal browser REPL. Documented Python kernels use Pyodide or Xeus Python, and contributors maintain an R kernel based on Xeus R. Interactive visualization support includes Altair, bqplot, ipywidgets, matplotlib, and Plotly. Users can create, edit, save, upload, and download files in the browser, where files are stored by default in IndexedDB. Data stays there unless an enabled extension sends it to an external service or notebook code uses the browser’s fetch mechanism. JupyterLite can be served as static HTTP(S) assets, embedded in another application, or deployed to supported static hosts without a dedicated application server. Browser storage is limited, though the documentation says smaller uploads up to about 50 MB should be fine. Some Python packages may not work because WebAssembly kernels cannot use certain native extensions, system libraries, threading, or filesystem access patterns. Where supported, a JupyterLite site can be installed as an application. The project says only its two latest releases are actively supported.

NextLeet Playground has no write-up on Specifiction yet; its figures are above.