`@peculiar/x509` is a TypeScript/JavaScript library that simplifies the creation, parsing, and validation of X.509 certificates and certificate requests. It's built on top of `@peculiar/asn1-schema` and provides an easy-to-use API for generating self-signed certificates, creating certificate signing requests (CSRs), building certificate chains, and exporting certificates to PKCS#7 format. This library is ideal for developers working on applications that require X.509 certificate management, such as secure communication systems, authentication services, or PKI implementations.