XML-RPC is a network protocol that lets one program call procedures provided by another program, even when they run on separate computers or use different programming languages. It encodes requests and responses as XML, with HTTP commonly used to carry them between systems. A request identifies a procedure and supplies its arguments; the receiving service processes the call and returns a result or an error. XML-RPC offered a relatively straightforward way to connect software across a network, though newer APIs and protocols are also widely used. The category includes an XWiki entry, a name associated with wiki software.