  Software systems are increasingly depending on data, particularly with the
rising use of machine learning, and developers are looking for new sources of
data. Open Data Ecosystems (ODE) is an emerging concept for data sharing under
public licenses in software ecosystems, similar to Open Source Software (OSS).
It has certain similarities to Open Government Data (OGD), where public
agencies share data for innovation and transparency. We aimed to explore open
data ecosystems involving commercial actors. Thus, we organized five focus
groups with 27 practitioners from 22 companies, public organizations, and
research institutes. Based on the outcomes, we surveyed three cases of emerging
ODE practice to further understand the concepts and to validate the initial
findings. The main outcome is an initial conceptual model of ODEs' value,
intrinsics, governance, and evolution, and propositions for practice and
further research. We found that ODE must be value driven. Regarding the
intrinsics of data, we found their type, meta-data, and legal frameworks
influential for their openness. We also found the characteristics of ecosystem
initiation, organization, data acquisition and openness be differentiating,
which we advise research and practice to take into consideration.
