Since last week you can download the Open Source version of Toonz, called OpenToonz. It's advertised as the software used to create Studio Ghibli films like Spirited Away and TV shows like Steven Universe and Futurama. On the website of Digital Video, creators of the software, we find the following information:
Digital Video, the makers of TOONZ, and DWANGO, a Japanese publisher, announced today they have signed an agreement for the acquisition by Dwango of Toonz, an animation software which was independently developed by Digital Video (Rome, Italy).
Digital Video and Dwango agreed to close the deal under the condition Dwango will publish and develop an Open Source platform based on Toonz (OpenToonz). Effective Saturday March 26, the TOONZ Studio Ghibli Version will be made available to the animation community as a free download.
OpenToonz will include features developed by Studio Ghibli (*Toonz Ghibli Edition) which has been a long time Toonz user. Through OpenToonz, Dwango will create a platform that will aim to have research labs and the animated film industry actively cooperating with each other.
With this agreement in place, Digital Video will move to the open source business model, offering to the industry commissioning, installation & configuration, training, support and customization services while allowing the animators’ community to use a state of the art technology at no cost.
Digital Video will also continue to develop and market a Toonz Premium version at a very competitive price for those companies willing to invest in the customization of Toonz for their projects.
I can not say too much about my experience. I've just installed the program and I customized the interface windows and some shortcuts.
The software is not 100% stable for now, but users have already begun to share knowledge and tutorials through the social media.
OpenToonz Facebook GroupOpenToonz users forum