Pencil2D

Pencil2D is a simple 2D animation, drawing, and painting application that lets you create traditional hand-drawn animation using both bitmap and vector graphics. Lightweight and easy to use so you can focus on animating and not on what button to hit next. Seamlessly switch between raster and vector workflows, allowing you to sketch, ink & paint on the go. Pencil2D is cross-platform and runs on Windows, macOS, Linux & FreeBSD. Pencil2D is completely open source and free to use, even commercially!