OpenChrom is a cross-platform GUI for chromatography and mass spectrometry. It is able to import binary and textual chromatographic data files, such as *.D chromatograms from Agilent Technologies or NetCDF. A basic set of methods to detect baselines, peaks and to integrate peaks in a chromatogram are implemented. Preprocessing steps, e.g. To remove certain mass fragments (m/z) such as nitrogen (28) or water (18), are supported by applying filters on the chromatogram or mass spectrum. Extensions are welcome, as OpenChrom is open source and uses a flexible approach, which allows others to implement their own methods, algorithms, filters, detectors or integrators.