HugeMCE was created because TinyMCE bait and switched users by growing a base on the MIT License and moving to GPLv2 in the latest version to push users to a commercial pay by use license. HugeMCE forks from the v6.8.x version that was still the MIT license to continue supporting those copyleft behind after the fact.
Origin thread:
https://github.com/tinymce/tinymce/issues/9453