This software for producing a 2D animation. It is based on the software "Toonz", which was developed by Digital Video S.p.A. in Italy, customized by Studio Ghibli, and has been used for creating its works for many years. Dwango launches this OpenToonz project, in cooperation with Digital Video and Studio Ghibli. This software can be used by anyone free of charge, no matter whether the purpose of use is commercial or not. This is available as an open source, so that users can modify its source code freely. We aim to develop a new platform for connecting the academic research into frontline animation production.