OpenMS is an open-source C++ library for LC/MS data management and analyses. It offers an infrastructure for the rapid development of mass spectrometry related software. It comes with a vast variety ready-to-use tools for proteomics and metabolomics data analysis and powerful 2D and 3D visualization. OpenMS offers analyses for various quantitation protocols, including label-free quantitation, SILAC, iTRAQ, SRM, SWATH. OpenMS supports the Proteomics Standard Initiative formats for MS data. The OpenMS Proteomics Pipeline is a pipeline for the analysis of HPLC-MS data. It consists of several small applications that can be chained to create analysis pipelines tailored for a specific problem. The TOPP tools are divided into several subgroups: - Graphical Tools - File Handling - Signal Processing and Preprocessing - Quantitation - Map Alignment - Protein/Peptide Identification - Protein/Peptide Processing - Targeted Experiments - Peptide Property Prediction - Misc