Toonz is an animation software solution used by studios like Studio Ghibli and has been in development for more than two decades. Earlier this month it was announced Toonz would be open-sourced and then a few days back the code was published as OpenToonz. While Toonz/OpenToonz originally didn't have Linux support, patches are emerging to allow this high-end animation software to run on Linux.
There is this issue tracker
about getting OpenToonz running on Linux. There's also this pull request
about some changes to get OpenToonz compiling for Linux.
However, it seems there is still more work needed before OpenToonz will still be stable on Linux. If you are wanting to learn more about the OpenToonz software in general, see their GitHub project site