Inviwo is an extendable C++ framework for easy prototyping of interactive applications. It provides a network editor for the designing of data flow networks, which are automatically evaluated and executed to produce output on one or more output processors (typically a canvas). The data flow in such a network runs from top to bottom, and the nodes are referred to as processors. Besides these processors two more first class objects exist. Ports, which are used to exchange data in between processors, and properties, which define the state of a processor.


Processors are the primary objects the user interacts with inside the network editor. Usually, they are dragged from the processor list on the left onto the network editor, before they are connected. Processors receive input data and generate output data through ports, whereby the ports on the top boundary are referred to as inports, and the ports on the bottom boundary are referred to as outports. Each processor has a set of properties, which define its current state. Upon selection of a processor in the network editor, its properties are shown in the property list on the right, where they can be edited.


Processors can exchange information in two ways. First, they can exchange data through their ports, whereby equally colored ports are of same type and can thus exchange data. Port connections can be established by connecting two ports via drag-and-drop. Besides the ports, the properties of a processor can be linked in order to synchronize their values. Links can be established by creating a connection between the semicircles of two processors.

To distinguish processors in a network, they have unique identifiers which can be edited by the user. Initially the identifier will be equal to the type of the processor, which is shown in italic below the identifier. Furthermore, the processor shows whether it is correctly connected through the status light.