Appwrite is an open-source self-hosted backend server that abstracts and simplifies complex and repetitive development tasks behind a very simple REST API
DOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. It's written in JavaScript and works in all modern browsers (Safari, Opera (15+), Internet Explorer (10+), Firefox and Chrome - as well as almost anything else using Blink or WebKit). DOMPurify is written by security people who have vast background in web attacks and XSS. Fear not.