Stamen Design, with grant funding from the Knight Foundation, recently developed the first publicly compiled and open-licensed terrain data set for the globe. Although other free and open terrain data exist, this data set is intended to fill in gaps and allow users to help improve its coverage and resolution.
The intent is to create a medium- to high-resolution data set by creating a public repository of all the open data sets with a merged view of the best available data. The new data set will include instructions and processes for how the data can be stitched together.
Stamen Design is trying to contact people with details on available terrain data sets. Users can get involved by e-mailing email@example.com or posting directly to github.com/openterrain/openterrain/wiki/Terrain-Data. Once the data are compiled, the company intends to release updates to its base map styles with terrain-enhanced versions.
Read more here.