XML Validation with xmllint (libxml2)

node-xmllint is an Emscripten port of libxml2's `xmllint` utility, enabling XML and XSD schema validation directly within Node.js environments and web browsers. It provides a synchronous `validateXML` function that returns an object containing an `errors` array (or null if no errors). As of version 1.0.0, the package has not seen updates in approximately 8 years, indicating it is an abandoned project. Its key differentiator was bringing the battle-tested libxml2 C validation engine to JavaScript runtimes, supporting complex XML Schema Definitions directly, unlike simpler regex-based or DOM-parser-based validation methods available at the time. It was designed to integrate with older frontend bundling tools like Browserify via `browserify-shim` for browser usage. Newer, actively maintained alternatives exist that leverage WebAssembly for better performance and modern API design.