Very robust software for testing FPGA designs in various configurations of simulators/emulator environments from multiple vendors like XILINX etc. Some problems I have faced while using this tool were:- 1. You need to get used it well so as you can easily use all its features2- Lack of proper documentation3.- Documentation should be made more user friendly4- Not enough support available when required5 - UI could not fit into small mobile devices6- Support by vendor needs improvement7. It has become one stop shop solution for test cases generation & execution across different simulator platforms including Cadence Virtuoso / ModelSim v1384+.