GrobPaint

GrobPaint is a lightweight image editor that sits somewhere between MS Paint and Paint.NET. Built with vanilla JavaScript and a minimal Python backend, it runs on macOS, Linux, and Windows out of the box.

Layers with opacity and blend modes, a full set of selection tools (rectangular, magic wand, lasso), image adjustments, and sprite sheet export. About 5,000 lines of JS with no framework dependencies.

I built this because I wanted a simple Paint.NET alternative on macOS that didn't require a heavyweight app. Just run python grobpaint.py and start editing.