kage studio is a simple, free, and open source 2D animation software
https://sourceforge.net/projects/kage/files/latest/downloadhttps://kage.sourceforge.io/Kage Studio is a vector-based 2D Animation cross-platform Software for Windows, Mac OS, and Debian/Ubuntu GNU/Linux suitable for beginners, hobbyists, and soon even professionals.
Written with GTKmm 3.0, Kage Studio have a clean User Interface. Truly an Animation Software, not an airplane cockpit.
Kage Studio can export animation to HTML5 (canvas), PNG sequence, Spritesheet, SVG, video (MP4, MKV, OGV, AVI, MOV), and KonsolScript.
Features
Shape/Motion Tweening
Frame-by-frame Animation
Onion Skinning
Vector Editor
Minimalist/Simplistic UI
Layers
Export to MP4
Export to MKV
Export to OGV
Export to MOV
Export to AVI
Export to HTML5
Export to SVG
Export to PNG
Export to Spritesheet