COMBINE archive: One File To Share Them All

Background: With the ever increasing use of computational models in the biosciences, the need to efficiently and easily share models and reproduce the results of published studies is becoming more important. As part of this effort, various standards have been proposed that can be used to describe models, simulations, data or other essential information. These constitute various separate components that are required to reproduce a published scientific result. Results: In this work we describe the Open Modeling EXchange format (OMEX) that allows all the necessary information to be bundled together into one file. Together with the use of other COMBINE standard formats, OMEX is the basis of the COMBINE archive, a single file that supports the exchange of all the information necessary for a modeling and simulation experiment in biology. An OMEX file is a ZIP container that includes a manifest file, listing the content of the archive, an optional metadata file adding information about the archive and its content, and the files describing the model. The content of a COMBINE archive consists of files encoded in COMBINE standards whenever possible, but may include additional files defined by an Internet Media Type. Several tools supporting the COMBINE archive are available, either as independent libraries or embedded in modeling software. Conclusions: The COMBINE archive facilitates the reproduction of modeling and simulation experiments in biology by embedding all the relevant information in one file. Having all the information stored and exchanged at once also helps support building logs and audit trails. We anticipate that the COMBINE archive will become a significant help, as the domain moves to larger, more complex experiments such as multi-scale models of organs, digital organisms, and bioengineering.