Nathan Lovato is a game designer who often creates and shares tutorials, usually around open source software. Recently Nathan posted an introduction to using Krita’s 2D animation tools.
Krita is free professional open source painting program for Windows, Linux and Mac systems. It is made by artists, for concept artists, illustrators, matte and texture artists, and the VFX industry. Recently, version 3.0 introduced an animation toolset, letting you create frame-by-frame animation with the existing paint and layer tools.
The free illustration tool introduced features like animatable raster layers, onion skinning, image sequence support, along with a sprite exporter. If you have done any animation work within Flash, this might feel very familiar to you. Nathan’s GDquest has a whole Krita tutorial series that you can find here.