Synfig Studio is a free and open-source 2D animation software, designed as powerful industrial-strength solution for creating film-quality animation using a vector and bitmap artwork. It eliminates the need to create animation frame-by frame, allowing you to produce 2D animation of a higher quality with fewer people and resources. Synfig Studio is available for Windows, Linux and MacOS X.
Synfig supports a multitude of layers of various types; geometric, gradients, filters, distortions, transformations, fractal and a few others.
Full-featured bone system allows to create cutout animation using bitmap images or control your vector artwork. The Skeleton Distortion layer allows to apply complex deformations to bitmap artwork.
Synfig has basic features for syncing your animation with soundtrack using Sound Layer. Linux users can get all benefits of full-featured audio editors through the JACK integration.