XML_XRD

XML_XRD is a PHP library to parse and generate Extensible Resource Descriptor (XRD) Version 1.0 and JRD (JSON-based) files.

XRD files are used for .well-known/host-meta files as standardized in RFC 6415: Web Host Metadata as well as in the LRDD (Link-based Resource Descriptor Discovery) files linked from it.

JRD files are used by WebFinger, which lets people use their e-mail address to do OpenID sign in.

The XRD format supercedes the XRDS format defined in XRI 2.0, which is used in the Yadis communications protocol.