From the developer: "SMSDemon is an SMS gateway server for sending and receiving SMS, ringtones, logos via a cell/mobile phone or GSM Modem connected to your PC or server. It will control and manage an unlimited number of GSM modems or mobile phones simultaneously and runs in the background as a Windows service with a professional management console. SMSDemon allows you to develop multiple messaging services and interactive applications that receive and send SMS such as; emergency alerting, information alerting, promotions, information retrieval, surveys, notifications, email integrations and anything else you can think of. It is a completely scalable solution that will allow you to start with a small number of devices and quickly expand with your business. Even though SMSDemon is a powerful program, it has been optimised so that it consumes minimal hard drive space and memory resources. In most cases it requires no more than the minimum installation requirements of your system."