Positioning systems, combined with inexpensive communication technologies, open interesting possibilities to implement real-time applications that monitor moving objects and that support decision making. This dissertation first discusses basic requirements for proactive real-time monitoring applications. Then, it proposes an architecture to deploy applications that monitor moving objects, are pro-active, explore trajectory semantics and are sensitive to environment dynamics. Lastly, this dissertation provides an example of how an application that monitors a fleet of trucks can become proactive, using unstructured text information available on Internet focused on road conditions change. The dissertation describes how to structure and geo-reference the text, using available geocoding services.