Tom Hengl is the Co-founder of OpenGeoHub foundation and Technical Director. In the SoilSpec4GG project, Tom leads the development of the OSSL DB, R packages and web services. In this talk, Tom reviews the novel Open Source Spectral Library (OSSL), consisting of multiple interrelated components. The first is a large database consisting of several continental and national collections of spectral data in both the visible-near infrared (VNIR) and mid-infrared (MIR) regions of the electromagnetic spectrum, as well as traditionally measured soil properties. These data can be accessed and visualized through the OSSL Explorer or directly worked with through an API or by downloading a snapshot of the entire database.