The concept of the Knowledge Bazaar as a paradigm for the development of Expert Systems, whereby knowledge bases are created dynamically using knowledge supplied by self appointed Internet communities is proposed. The idea espouses the creation of individual Knowledge Bazaars, operating in specific domains, but all operating through a generic Knowledge Bazaar XML Web application. Issues addressed include the provision of the service, XML rule representations and rule integrity. The concept is illustrated with a demonstration gardening Knowledge Bazaar that is currently operational.