The name KASIMIR is a german abbreviation for ’KAnalSIMulation Im Rechner’ (in English: ’Shock tube simulation on a computer’). The program simulates the physical phenomena inside a shock tube on a conventional personal computer; the calculation time is comparable low (usually less than one minute). It calculates the complete x,t-wave plan which is immediately displayed on the screen and provides information about the variables of state (e.g. pressure, temperature, density, shock velocity, chemical composition) at each position. Moreover, it is possible to display the temporal history or the spatial distribution of a state variable of interest. Therefore, KASIMIR is a powerful tool to design new shock tube experiments and to understand the experimental records.