After the massacre that was Warriors of the Wind, Hayao Miyazaki did not allow any of his films to be licensed by anyone. Eventually, he gave Disney another chance, but with a simple stipulation. He sent the executives across the pond a katana with a note saying "No Cuts". To this very day, no new Ghibli productions have ever been cut in the US.
Studio Ghibli used Toonz extensively from Princess Mononoke and on. After Arrietty it was customized inside the company. It's released in open source version as OpenToonz now.
...because Miyazaki actually does work with Italians now and then, unlike so many people who profess love to something far, far away.