Monokai JSON+ - Sublime Monokai Theme for JSON.
CKEditor - Real-time collaborative future-ready rich text editor
Editor.js - A block-styled editor with clean JSON output
Summernote - Summernote is a JavaScript library that helps users create WYSIWYG editors online.
Power JSON Editor - Power JSON Editor is a JSON editor for developers with Visual Tree View and multiple plugins like Array Table Editor and jq Processor, also with format converter plugins, it is easy to convert files between JSON, PLIST, YAML and TOML.
Froala Editor - Froala Editor is a WYSIWYG HTML editor that enables rich text editing capabilities for the applications.