The gateway software is provided for Member States' remote access to ECMWF computing and archiving facilities. Throughout the guide, the terms "gateway" and "ECaccess gateway" are used interchangeably. Gateways include a model for the management of "plugin" services. A plugin is a piece of code that handles requests/responses flowing through the gateway. Currently, there are plugins for incoming FTP, HTTP/S, X11, SSH and Telnet (MSgateways only) requests to ECMWF. Additional plugins are planned. On top of the SSH plugin the NX application can be used for interactive access to ECMWF. The ECMWF ECaccess gateway (hereafter referred to as "ECgateway") can be used on its own. Nevertheless, using a Member State ECaccess gateway (hereafter referred to "MSgateway") instead offers the following features and advantages over using the ECgateway on its own: