Keyv is a simple key-value storage with support for multiple backend adapters (MySQL, PostgreSQL, SQLite, Redis, Mongo, DynamoDB, Firestore, Memcached, and more).
You may also be interested in ...
Quill
Quill is a free, open source WYSIWYG editor built for the modern web. With its modular architecture and expressive API, it is completely customizable to fit any need.
Prism
Prism is a lightweight, extensible syntax highlighter, built with modern web standards in mind. It’s used in thousands of websites, including some of those you visit daily.
Accessibility cheat sheet
Practical approaches to Universal Design for making your website/webapp accessible to everyone.