The topography of Mars is a key parameter for understanding the geological evolution of the planet. Since 1997, the Mars Orbital Laser Altimeter (MOLA), launched in the frame of Mars Global Surveyor, has acquired more than 600 million topographic measurements. However, despite the high vertical accuracy of those profiles, the main limitation of this technique appears when topographic maps are required. To create a Digital Elevation Model (DEM) or a topographic map, an interpolation on individual MOLA measurements on regular grids is required. Calculating the global full-resolution Martian DEM requires very intensive computation and large disk capacities. Only a few teams throughout the world have computed a full resolution DEM from MOLA data. Even if a scientist is interested in a small area of Mars, numerous profiles have to be processed and extracted from 44 CD-ROMs. To facilitate the exploitation of the high potential of MOLA data, we propose an Internet application that allows any user to extract the individual MOLA measurements from all profiles over a given area and to process local DEMs of the surface of Mars with adjustable parameters of computation. This facility, developed in Interactive Data Language by Research Systems, Inc., allows users to select the zone of interest and the resolution of the output DEM. After online processing, various products in standard formats can be downloaded on the user's computer, including DEMs, individual MOLA points, list and map of the MOLA ground tracks used for the DEM generation, and a quality map. This map is computed by evaluating the distance between each point of the DEM and the closest measurements of the altimeter. Furthermore, IDL tools are supplied to facilitate data integration and use.