: a software package for large-scale cryo-electron tomography data preprocessing, community data sharing and collaborative computing.

Cryo-electron tomography (cryo-ET) and subtomogram averaging (STA) are becoming the preferred methodologies for investigating subcellular and macromolecular structures in native or near-native environments. Although cryo-ET is amenable to a wide range of biological problems, these problems often have data-processing requirements that need to be individually optimized, precluding the notion of a one-size-fits-all processing pipeline. Cryo-ET data processing is also becoming progressively more complex due to the increasing number of packages for each processing step. Though each package has its strengths and weaknesses, independent development and different data formats make them difficult to interface with one another. () is an extensible package for streamlining the interoperability of packages, enabling users to develop project-specific processing workflows. does this by maintaining an internal metadata format and wrapping external packages to manage and perform preprocessing, from raw tilt-series data to reconstructed tomograms. can also export these metadata between various STA packages. includes tools for archiving projects to data repositories, allowing subsequent users to download projects and directly resume processing. By tracking essential metadata, streamlines data sharing, which improves the reproducibility of published results, reduces computational costs by minimizing reprocessing, and enables the distribution of cryo-ET projects between multiple groups and institutions. provides a way for users to test different software packages in order to develop processing workflows that meet the specific needs of their biological questions and to distribute their results to the broader scientific community.