SDF is an XML file format that describes environments, objects, and robots in
a manner suitable for robotic applications. SDF is capable of representing and
describing different physic engines, lighting properties, terrain, static or
dynamic objects, and articulated robots with various sensors, and acutators. The
format of SDF is also described by XML, which facilitates updates and allows
conversion from previous versions. A parser is also contained within this
package that reads SDF files and returns a C++ interface.

WWW: https://bitbucket.org/osrf/sdformat/src/default/