Galileo offers to civilian users an increasing number of services, aiming at enhancing accuracy, availability, robustness and integrity of the navigation solution. Despite being available since the first transmission, the E5 AltBOC wideband signal has not gained popularity yet, mainly due to the challenges in handling such a large band and in processing a complex modulation. Nevertheless, it offers unprecedented standalone positioning accuracy. With the progress of electronics, we can foresee that hardware capable of capturing and processing such signals will be available soon also at mid-range prices, and in the future even in the mass-market segment. This paper describes the software implementation of an acquisition, tracking, data demodulation and navigation solution chain for Galileo E5 AltBOC signals, outlining opportunities and challenges. Considerations are supported by real Galileo data results, showing sub-meter stand-alone positioning accuracy.