Glaxnimate is a simple and fast vector graphics animation program.
OpenToonz
Software for the production of 2D animation.
Tupitube
TupiTube ( also known as Tupi 2D) is a free and open-source 2D animation software that is focused on usability for children, teenagers and amateur artists.
qStopMotion
qStopMotion is a fork of stopmotion for Linux.
Ch'íich'o'
Enve is a new open-source 2D animation software for Linux.
VPaint
A glimpse into the future of Graphic Design and 2D Animation
Synfig
Professional open-source 2D Animation Software for Linux.