Digital technologies have a significant impact on medical training. Growing popularity of virtual and augmented reality changes the trend into virtual simulators. We gave an overview of key market products in the field of medical simulators in order to define main aspects for development of our own system. These aspects are: open surgery, realistic visualization, and haptic feedback. We described in details each of them and how it was implemented in our system. For open surgery was used appendectomy as most common procedure of this type of the surgery. In order to achieve realistic visualization, we implemented three different approaches for creating realistic and accurate 3D models. For haptic feedback, we took Novint Falcon and enhanced it with our custom grip which provides additional degrees of freedom.