Abstract: A method and computer software architecture is presented for facilitating modification of execution of a software application without impacting the integrity of the original software. The present invention defines an inter-component messaging service which brokers or receives, evaluates and directs messages between components of the architecture. The architecture further integrates functionality into the individual components which re-directs a request back to the messaging service prior to completion of the functionality in the requested original component in order to determine the presence of any concerned extension components that have registered with the messaging service thereby making known their interest in having their functionality explored prior to completion of the execution of the requested component.