MultiCellDS (Multicellular data specification), an outgrowth of the earlier MultiCellXML project, aims to create a data standard for sharing multicellular experimental, simulation, and clinical data. Our ultimate goal is to foster a community that develops user-friendly tools that can read, write, and recombine data into better simulations and analyses for multicellular biology and predictive medicine. As part of this effort, we are developing MultiCellDB: a repository for a curated library of digital cell lines and peer-reviewed simulation and experimental data. A novel part of MultiCellDS is the digital cell line: a digital analogue of experimental cell lines that will help to collect biophysical cell line measurements coming from many research groups and make them readily accessible to an ecosystem of compatible computational models. You can learn more about digital cell lines and other core ideas on this page. We are currently preparing a draft of the upcoming MultiCellDS 1.0 specification. After a multiple rounds of comment and review by a multidisciplinary review panel and the general public, we target an October 2016 release of the data specification and software support tools.