OnLAN Messenger is a client-server multi-user application for message and file exchange. This product has been specially developed for use inside corporate networks (enterprise instant messaging) therefore its functions and settings in the first place are oriented on corresponding to the needs of the different level companies for safe secure handy and controllable instant messaging solution. OnLAN Messenger service consists of three program modules: Server part(details): * OnLAN Server (server) * OnLAN Monitor (monitor) Client part(details): * OnLAN Messenger (client) OnLAN Server module supports different types of exchange between service clients organizing access to the database. There are two types of administration: console and web-interface with ability to separate administrators'' roles. OnLAN Monitor module is a support module for OnLAN Server. It starts or stops server (automatically or manually) and provides server recovery if error occurred. Both of these modules are system services and work in close contact with server computer operating system core. They are installed on the same server computer therefore monitor is working in ''''local'''' mode. There''s also an opportunity to monitor server working from any computer in the company LAN in the remote mode. Client part of OnLAN Messenger service consists of only one module OnLAN Messenger(client). It should be started on every machine that is connected to the messaging service. All of the OnLAN Messenger service program modules have been developed for OS Windows (95-XP) with minimal system requirements: Pentium 200 Mhz RAM 64Mb SVGA (256 colors 800x600) mouse.