DD4hep is a software framework for providing a complete solution for full detector description (geometry, materials, visualization, readout, alignment, calibration, etc.) for the full experiment life cycle (detector concept development, detector optimization, construction, operation). It offers a consistent description through a single source of detector information for simulation, reconstruction, analysis, etc. It distributed under the GPLv3 License
For information about how to install DD4hep see this page
Use's Manuals can be found here.
The Code Reference can be found here.
Comprehensive release notes can be found under doc/ReleaseNotes.md