IVI is a graphical front-end for various simulators. IVI allows the user to control simulation and view signal waveforms as the data is produced by the simulation.
IVI stresses an interactive approach to design testing and debugging


Signal waveforms may be examined during simulation
Signals may be added to the waveform at any point during simulation

Multiple wave-data files may be open at a time
The simulation may be restarted after the design is recompiled, preserving traced signals and waveform-window configuration

Simulation operations can be automated using the TCL scripting language