The real-time multi-task simulation of a 3-leg 6-DOF high performance platform system based on RT-Linux operation system is presented in this paper. The new architecture is setup by three extensible legs sliding on three linear slide-rail each actuated by a synchronous linear servo motor. The extensible legs are actuated by inductive AC servo motors. In the meantime, the inverse and forward kinematical equations describing the motion of the platform system are derived. This kind of architecture using the hybrid (linear and AC) motors yields high performance of motions, especially in speed and working space. The novel result of maximal working angles is the significant contribution of this architecture. The platform system is operated in the RT-Linux real-time multi-task executive environment, which is superior to windows, including: (a) RT-Linux real-time is hard real-time, (b) RT-Linux real-time operation system is free, (c) Multi-task can be scheduled by the optimum preemptive static scheduling algorithm. We have demonstrated the dynamic behavior of platform in the RT-Linux window and the OpenGL 3D/VR multi-medium.