MMass is a free mass spectrum viewer/analyzer in which the following proteomics-related tasks can be performed:

- Open raw text, mzXML and mzData mass spectra;
- Define peak lists;
- Powerful mass spectrum viewer (zoom, cursor...);
- Data recalibration;
- Protein-only simulations;
- Online Mascot searches.
The software can be easily extended by additional Python modules. This package contains the platform-independent parts of the software.