Installer is an application that helps you to install and configure Joomla on your web site. Follow the next steps at Installer. This application should be deleted as soon as installation is completed.
XML-RPC, known as eXtensible Markup Language Remote Procedure Call, is a method of sharing messages between client and server. Note that from version 1.6 onwards, the XML-RPC application is no longer included in the Joomla distribution.