BioMAJ (BIOlogie Mises A Jour) is a workflow engine dedicated to data synchronization and processing. It automates the update cycle and the supervision of the locally mirrored data repository. The application is generalist, but was applied in the bioinformatics field for biological data bank management. The packaging includes workflow and indexing post-processing scripts for most used biological data banks. Developed in Java and Ant, the application is compatible with various Unix-based systems.