Spine - Spine is 2D animation software designed specifically for software and game development.
CKEditor - Real-time collaborative future-ready rich text editor
Live2D Cubism - Live2D is the world's first drawing technology to enable 3D rendering of 2D images.
Summernote - Summernote is a JavaScript library that helps users create WYSIWYG editors online.
Synfig Studio - Just another WordPress site
Froala Editor - Froala Editor is a WYSIWYG HTML editor that enables rich text editing capabilities for the applications.