1. A computer-implemented method for performing a workflow with reference to user code related to the workflow, said computer-implemented method comprising: defining a componentized workflow that is visually modeled having a plurality of activities; creating an uncompiled representation of the workflow serialized in an extensible orchestration markup language (XOML) format for serializing the workflow; receiving the user code beside of the workflow from a user for association with one or more of the plurality of activities of the workflow where each activity has at least three parts: metadata, instance data, and execution logic wherein the metadata defines data properties for configuration of the workflow and the plurality of activities are associated with runtime execution semantics and behavior; compiling the user code; executing the defined workflow as a function of the created, uncompiled representation of the workflow and the compiled user code associated with the workflow wherein the metadata is transferred to the uncompiled representation of the workflow and stored in author time fields; and dynamically modifying the uncompiled representation of the workflow to affect execution of the workflow model without compiling the workflow while the defined workflow is being executed, wherein the modification of the uncompiled representation is directly reflected in the workflow and the user code bedside in real time.