r509 is a Ruby gem built using OpenSSL that is designed to ease management of a public key infrastructure. The r509 API facilitates easy creation of CSRs, signing (and parsing!) of certificates, revocation (CRL/OCSP), and much more. Together with projects like r509-ocsp-responder and r509-ca-http it is intended to be a complete (RFC 3280/5280) certificate authority for use in production environments.