Molybdenum oxides and sulfides were studied using resonant inelastic X-ray scattering (RIXS). The 2p3/23d Mo RIXS planes show a rich structure with considerably more spectral information than in conventional X-ray absorption near edge structure (XANES) spectroscopy. The spectra were simulated using FEFF9 giving generally good agreement and detailed electronic information can be derived. The reference materials serve as a starting point for detailed electronic and geometric investigations of a broad range of compounds. In particular, this can provide insights in the properties and performance of unknown and changing materials like those in catalysis.