OpenToonz

Yes, OpenToonz can be used free of charge for both commercial and non-commercial projects.

For Windows, you need Microsoft Windows 7 SP1/8.1/10 (64bit), an Intel Core i series processor, 4GB or more RAM, 500 MB or more available storage space, and a monitor resolution of 1280 x 1024 or higher. For macOS, you need macOS 10.14 (Mojave) or later, an Intel Core i series processor, 4 GB or more RAM, 500 MB or more available storage space, and a monitor resolution of 1280 x 1024 or higher.

Yes, OpenToonz is open-source, and its source code can be modified freely under the terms of the New BSD License.

Yes, there is a Google group for users to solve problems, request functional improvements, report bugs, and have discussions. Additionally, there is a developers forum on GitHub for development-related topics.

GTS is a scanning tool developed by Studio Ghibli that specializes in animation. It is available for Windows only and not for macOS.

You can join the OpenToonz Google group to report bugs, request functional improvements, and discuss with other users. For development-related topics, you can use the developers forum on GitHub.

Yes, Dwango has developed an SDK for plug-in effects, and effects developed by their machine learning research and development team are available. These include effects for automatically changing picture styles using deep learning technology and producing affected incident light like those in classic works.