mzCloud is a web-based mass spectral database that comprises a curated collection of high and low resolution tandem mass spectra acquired under a number of experimental conditions which address the problem of spectra reproducibility. Spectra are filtered, manually recalibrated and annotated by fragments processed by quantum-chemical methods. Data are freely searchable by spectrum, spectral tree, (sub)structure, fragment, precursor ion, mass-to-charge ratio, monoisotopic mass and chemical name. In addition to the spectral and structural data, mzCloud also includes break-down curves.
HighChem (the software producer) is affiliated with Thermo Fisher Scientific and the database is therefore at the moment dominated by mass spectra from orbital ion trap instruments.