From Remote Utilities:
Remote Utilities Server (formerly Gateway Mediation Server) is a free program that runs locally on your premises and provides remote access mediation service. RU Server works with Remote Utilities remote desktop software. The program consists of a service and Administrator's console. The service is run on the gateway PC while the Administrator's console is used to connect to server and administer it. RU Server allows remote support companies and helpdesk providers to have fully independent remote support solution where all connections go through the server that they control. Also, RU Server allows helpdesks to share their connection list (address book) easily using RU Server's built-in sync capabilities.
Version 18.104.22.168: Centralized permissions management in the RU Server. Users and groups can be created, and each user or group assigned different permissions for accessing the address books, synchronized through the server.
Additional authorization method to the Host - "Custom server security". With this authorization method the RU server acts as a "domain controller" for the Host. You can use accounts created on the RU server to authorize on the Host.
Auto-import - Hosts connected to the self-hosted server (RU Server) are automatically added to a designated address book folder.