Business rules provide an elegant solution to manage dynamic business logic by separating business knowledge from its implementation logic. The drawback of most existing business rule approaches is the lack of standardization and interoperability. The lack of service-orientation and remote accessibility of business rule engines makes it hard to use business rules in distributed environments. This paper contributes the design and implementation of VIDRE (Vienna Distributed Rules Engine), a service-oriented business rule engine based on RuleML. VIDRE enables enterprise applications to access business rules as easy as accessing a database, by exposing rules as Web services. VIDRE uses RuleML as an interlingua to represent facts, rules, and queries. One of the main contributions of the VIDRE approach is the ability to distribute rules and facts across various rule engines, therefore, enabling powerful ways of separating and executing business rules within intra- and interorganizational boundaries.