The GGU-SLAB program can analyse slabs using the subgrade reaction modulus and the con- strained modulus methods. The finite-element method using triangle elements is employed to solve the differential equation. The subgrade modulus profile can be varied as required with al- most no constraints. The constrained modulus distribution can be defined via stratigraphic profiles and an interpolation mesh. This allows any imaginable stratigraphy to be generated. Further important capabilities include: • limiting depth analysis to DIN 4019 for constrained modulus method, • any type of slab boundary including with holes, • linearly variable subgrade within an element, • beam elements for modelling footing beams, for example, • single springs, perpendicular to slab, e.g. for modelling piles. The program system includes a powerful mesh generator and easy-to-use routines for comfortable evaluation of the analysis results (contours, 3D graphics, etc.). The application is designed to allow simple data input or modification. The input is immediately shown on the screen, giving you optimum control over what you are doing. Graphics output sup- ports the true-type fonts supplied with WINDOWS, so that excellent layout is guaranteed. Colour output and any graphics (e.g. files in formats BMP, JPG, PSP, TIF, etc.) are supported. DXF files can also be imported by means of the integrated Mini-CAD module (see the "Mini-CAD" man- ual). It is not the aim of this manual to offer an introduction to the finite-element method. For details of the finite-element method, please see O. C. Zienkiewicz, "Methode der Finiten Elemente" ("Finite- Element Methods") , Carl Hanser Verlag Munich, Vienna, 1984. The program system has been used in a large number of projects and has been thoroughly tested (using analytical solutions and in comparison with other FEM applications). No faults have been found. Nevertheless, liability for completeness and correctness of the program and the manual, and for any damage resulting from incompleteness or incorrectness, cannot be accepted.