Invision - Prototyping and collaboration for design teams
CKEditor - Real-time collaborative future-ready rich text editor
Marvel - Turn sketches, mockups and designs into web, iPhone, iOS, Android and Apple Watch app prototypes.
Summernote - Summernote is a JavaScript library that helps users create WYSIWYG editors online.
UXpin - Design is really about solving problems. UXPin is the UX Design Platform that gets that right.
Froala Editor - Froala Editor is a WYSIWYG HTML editor that enables rich text editing capabilities for the applications.