Business requirements are changing faster than applications can be created or adapted. Most of these requirements are related to business rules. Business rules are precise statements that describe, constrain and control the structure, operations and strategy of a business. Traditionally, business rules have been scattered, hard-coded and replicated by different applications. As a result, it has been difficult to adapt them to new requirements quickly. In recent years, there has been a trend to extend databases with powerful rule-processing capabilities leading to so-called active databases. They rely on Event-Condition-Action rules (ECA-rules) to provide automatic execution of predefined operations in response to the occurrence of certain events. The goal of this work is to provide a flexible ECA-rule processing functionality in order to support the requirements of open distributed heterogeneous environments. This mechanism is implemented as a separate, autonomous and flexible active functionality service. This is materialized as a service-based architecture which is founded on three main pillars: an ontology-based infrastructure, event notifications and service-oriented principles.