zasper2.1.0

Zasper lets users open, edit, run, and save Jupyter notebooks in a Linux IDE built for responsive interactive computing. Built by Prasun Anand as an alternative to JupyterLab, it speaks Jupyter’s wire protocol and runs existing notebooks with their registered kernels. It is open-source Education software for Linux users working with notebooks in educational settings.

The program is delivered as one static binary and is designed for massive concurrency, combining a small memory footprint with high speed and support for thousands of simultaneous connections. Compared with Jupyter Server, it is described as using up to five times less CPU and up to 40 times less RAM, with the advantage increasing as concurrency rises. In a comparison on Apple M4 hardware using 10 requests per second per kernel across two to 100 concurrent kernels, Zasper stayed responsive while Jupyter Server began losing kernel connections beyond 64 and had lost them all at 100; higher throughput, lower latency, and resilience under very high loads are central goals.

Zasper reads and writes .ipynb files directly, so notebooks move between it and JupyterLab without conversion, import steps, or a new workspace, while using the same kernels registered once. It saves files byte-for-byte as Jupyter would, preserves each notebook’s nbformat version such as 4.2, and avoids silent upgrades that can create diffs or merge conflicts. HTML, PNG, JPEG, SVG, LaTeX through KaTeX, Plotly figures, ipywidgets, and JSON outputs all render, while widget state remains in the kernel and becomes a placeholder after that kernel ends.

Saves are atomic: Zasper writes beside the notebook and renames the completed file into place, preventing a crash from leaving a partial notebook. JupyterLab extensions do not load because Zasper uses its own extension model. Version 2.1.0 requires Linux with snapd and runs on x86_64 (amd64) systems.