SeismoStruct is an award-winning Finite Element package capable of predicting the large displacement behaviour of space frames under static or dynamic loading, taking into account both geometric nonlinearities and material inelasticity. Concrete, steel, frp and sma material models are available, together with a large library of 3D elements that may be used with a wide variety of pre-defined steel, concrete and composite section configurations. The program has been extensively quality-checked and validated, as described in its Verification Report. Some of the more important features of SeismoStruct are summarised in what follows: Completely visual interface. No input or configuration files, programming scripts or any other time-consuming and complex text editing requirements. Full integration with the Windows environment. Input data created in spreadsheet programs, such as Microsoft Excel, may be pasted to the SeismoStruct input tables, for easier pre-processing. Conversely, all information visible within the graphical interface of SeismoStruct can be copied to external software applications (e.g. to word processing programs, such as Microsoft Word), including input and output data, high quality graphs, the models' deformed and undeformed shapes and much more. With the Wizard facility the user can create regular/irregular 2D or 3D models and run all types of analyses on the fly. The whole process takes no more than a few seconds. With the Building Modeller the user can create real regular or irregular 3D reinforced concrete models of up to 20 storeys within minutes. Eight different types of analysis: dynamic and static time-history, conventional and adaptive pushover, incremental dynamic analysis, eigenvalue, non-variable static loading, and response spectrum analysis. The applied loading may consist of constant or variable forces, displacements and accelerations at the nodes, as well as distributed element forces. The variable loads can vary proportionally or independently in the pseudo-time or time domain. The program accounts for both material inelasticity and geometric nonlinearity. A large variety of reinforced concrete, steel and composite sections are available. The spread of inelasticity along the member length and across the section depth is explicitly modelled in SeismoStruct allowing for accurate estimation of damage accumulation. Numerical stability and accuracy at very high strain levels enabling precise determination of the collapse load of structures. The innovative adaptive pushover procedure. In this pushover method the lateral load distribution is not kept constant but is continuously updated, according to the modal shapes and participation factors derived by eigenvalue analysis carried out at the current step. In this way, the stiffness state and the period elongation of the structure at each step, as well as higher mode effects, are accounted for. In particular the displacement-based variant of the method, due to its ability to update the lateral displacement patterns according to the constantly changing modal properties of the system, overcomes the inherent weaknesses of fixed-pattern displacement pushover, providing superior response estimates. SeismoStruct possesses the ability to smartly subdivide the loading increment, whenever convergence problems arise. The level of subdivision depends on the convergence difficulties encountered. When convergence difficulties are overcome, the program automatically increases the loading increment back to its original value. SeismoStruct's processor features real-time plotting of displacement curves and deformed shape of the structure, together with the ability of pausing and re-starting the analysis. Performance criteria can also be set, allowing the user to identify the instants at which different performance limit states (e.g. non-structural damage, structural damage, collapse) are reached. The sequence of cracking, yielding, failure of members throughout the structure can also be, in this manner readily obtained. Advanced post-processing facilities, including the ability to custom-format all derived plots and deformed shapes, thus increasing productivity of users. AVI movie files can be created to better illustrate the sequence of structural deformation