Presentation: NADDI 2015: Crowdsourcing DDI Development: New Features from the CED2AR Project Perry, Benjamin; Kambhampaty, Venkata; Brumsted, Kyle; Vilhuber, Lars; Block, William Recent years have shown the power of user-sourced information evidenced by the success of Wikipedia and its many emulators. This sort of unstructured discussion is currently not feasible as a part of the otherwise successful metadata repositories. Creating and augmenting metadata is a labor-intensive endeavor. Harnessing collective knowledge from actual data users can supplement officially generated metadata. As part of our Comprehensive Extensible Data Documentation and Access Repository (CED2AR) infrastructure, we demonstrate a prototype of crowdsourced DDI, using DDI-C and supplemental XML. The system allows for any number of network connected instances (web or desktop deployments) of the CED2AR DDI editor to concurrently create and modify metadata. The backend transparently handles changes, and frontend has the ability to separate official edits (by designated curators of the data and the metadata) from crowd-sourced content. We briefly discuss offline edit contributions as well. CED2AR uses DDI-C and supplemental XML together with Git for a very portable and lightweight implementation. This distributed network implementation allows for large scale metadata curation without the need for a hardware intensive computing environment, and can leverage existing cloud services, such as Github or Bitbucket. Ben Perry (Cornell/NCRN) presents joint work with Venkata Kambhampaty, Kyle Brumsted, Lars Vilhuber, & William C. Block at NADDI 2015.