Open Source Linux Animation Software

Synfig is a powerful, industrial-strength vector-based 2D animation software package, designed from the ground-up for producing feature-film quality 2D animation with fewer people and resources.

With the Spritesheet Cutter (also called Map Editor or Level Editor) you can cut/share/export/move/name single or multiple sprites using drag & drop. There is a copy mode so maps can be created. Sprites are numbered left to right/top to bottom or randomly. Sprites can be added to a sheet and saved as a whole. An animation preview is included. Spritesheet Cutter cannot create GIFs, but there are better solutions. Color selections can be converted to transparency.

Pencil2D is an animation/drawing application for OSX, Windows and Linux. It lets you create traditional hand-drawn animations (cartoons) using both bitmap and vector graphics.