Abstract:4.1 Introduction4.2 A short mass spectrometry primer4.3 Metabolomics and metabonomics4.4 Data types4.5 Metabolomics data processing4.6 Metabolomics data processing using the open source workflow engine, KNIME4.7 Open source software for multivariate analysis4.8 Performing PCA on metabolomics data in R/KNIME4.9 Other open source packages4.10 Perspective4.11 Acknowledgments