sdf-format is a xml format created in 2012.

SDF is an XML format that describes objects and environments for robot simulators, visualization, and control. Originally developed as part of the Gazebo robot simulator, SDF was designed with scientific robot applications in mind. Over the years, SDF has become a stable, robust, and extensible format capable of describing all aspects of robots, static and dynamic objects, lighting, terrain, and even physics.

• sdf-format website
• sdf-format first developed in https://www.openrobotics.org/foundation
• sdformat.org was registered in 2013
• Read more about sdf-format on the web: 1.