A dataflow environment based on a client/server approach, called WiT, enables dataflow graphs to be executed efficiently with little overhead. Data tokens are managed by reference and reside on servers until either data is requested for viewing or required by another server. An enhanced fire-on-any behaviour greatly simplifies the design of many simple graph constucts such as multiplexors or crossbars which are overly complicated when implemented with classical dataflow contraints. Sync tokens are used to accommodate the need for synchronizing data, especially useful when controlling hardware. A hierarchical scheduler maintains execution sequence in a logical progression across multiple sub-graphs to provide a server an opportunity to generate well structured standalone code suitable for real-time target hosts. An example of WiT using hundreds of nodes and links to model Datacube devices for a realistic application is presented. The use of hierarchical operators serves to reduce such a complex application to a manageable level.