The VST (VLT Survey Telescope) active optics software must basically provide the analysis of the image coming from the wavefront sensor (a 10x10 subpupils Shack Hartmann device) and the calculation of primary mirror forces and secondary mirror displacements to correct the aberrations of the optical system, instrinsic or originated for thermal and gravity reasons. After the telescope commissioning the VST will be operated by ESO. In this framework, INAF-OAC staff was committed to design and realize the software in a VLT-compliant way. This will smoothen the integration, operation and maintenance of the telescope in the Paranal observatory
