The INGV Spectral Library is an open-source, modular platform for the management, exploration, and analysis of spectral data across Earth Science and Cultural Heritage applications. Unlike many existing spectral libraries, which are often domain-specific and provide limited support for preliminary data interaction, the INGV Spectral Library combines structured metadata organisation, georeferenced sample exploration, and integrated spectral pre-processing tools within a single interactive environment. The platform enables users to browse heterogeneous datasets acquired from different instruments and spectral ranges, compare multiple spectral signatures simultaneously, and apply first-derivative analysis, continuum removal, and sensor-based spectral resampling through spectral response...