The data portal DDI on Rails accompanies researchers throughout the entire course of their research projects from conception to publication/citation.

The system offers researchers the possibility to explore the data, to compile personalized datasets, and to publish results on the publication database.

In contrast to similar products, DDI on Rails is study-independent and open-source, is able to document data with multiple versions/distributions and the specific characteristics of a longitudinal study, and is easy to use.

Related Projects
r2ddi extracts metadata from Stata files, generating DDI-Codebook XML.
soepR uses the API in DDI on Rails to fetch metadata directly into R. In particular, it can run generated scripts from the basket without any copy and paste.
testdata offers a comprehensive testcase for developing software and workflows, considering the special needs of a panel study like the SOEP.