In this paper we introduce a workflow management system, called WebFlow, which is based on the world wide web and Java as its basic technologies. Java is used as the build time (modeling) language to define workflows as well as the implementation language for the run time workflow enactment. Due to the object-orientation of Java modular and extendible workflow types are possible. Modification of workflows is supported even at run time. Using WWW and Java eases the implementation effort of the workflow engine, since HTTP and the Java API already include functionality which needs not to be implemented anew. This is uploading and downloading of workflow applets and documents, authentication of clients, digital signing and especially the execution of workflows at the client site by the Java virtual machine. Thus, a very simple control server is sufficient, since the applets constituting the workflow coordinate themselves to a large extent. Webflow aims at application scenarios requiring f...