Dropbox - Online Sync and File Sharing
CKEditor - Real-time collaborative future-ready rich text editor
ownCloud - ownCloud is an open source project enabling businesses to host their own cloud storage while maintaining regulatory and compliance needs.
Summernote - Summernote is a JavaScript library that helps users create WYSIWYG editors online.
Google Drive - Access and sync your files anywhere
Froala Editor - Froala Editor is a WYSIWYG HTML editor that enables rich text editing capabilities for the applications.