CKEditor 4 and CKEditor 5 are easy-to-implement open source JavaScript WYSIWYG rich text editors for any web browser. CKEditor Ecosystem has 2 very distinct rich text editors as well as image upload and collaboration solutions.
CKEditor 4
First and oldest member of CKEditor Ecosystem family; CKEditor 4 is a WYSIWYG rich text editor compatible with a wide range of browser support including the legacy ones. It has native integrations to Vue, React and JQuery and vast documentation.
Used by millions, it has been around since 2013 and has a very wide range of features and plugins including Paste from Word, tables, media embed, auto-complete, mentions and emoji; advanced content filtering, etc. CKEditor 4 is available under GPL, LGPL and MPL Open Source and commercial licenses.
CKEditor 5
The new member of the family CKEditor 5, has a different and modern approach to rich text than its predecessor has been written from scratch in ES6. It does not share many similarities with its sibling, except the name. CKEditor 5 has an MVC-based engine with a custom data model and virtual DOM. Its modular and plugin-based architecture is customizable.
CKEditor 5 has native integrations with Angular, React, Vue.js, npm, webpack, Electron, etc. CKEditor 5 also has many features like its predecessor, auto-formatting and paste from Word, mentions, placeholders, media embeds and tables…
Apart from these its most notable features are its premium collaborative editing features; real-time collaboration, track changes and comments which are powered by Operational Transformation. CKEditor 5 is available under GPL 2+. But if you are running a project with an OSS license incompatible with GPL 2+, you can contact them for a free CKEditor 5 license.