For humanoid robotics, an accurate kinematic model of the robot is critical for control and estimation purposes. A very common file format to represent a robot is a URDF file (http://wiki.ros.org/urdf). Creating a URDF file by hand is possible, but very tedious and prone to mistakes. A good approach is to use a CAD tool which can generate a URDF file problematically.
Onshape to Robot (https://github.com/Rhoban/onshape-to-robot) is a great tool for this purpose. Using an assembly of the NUgus platform (shown below) with all the joints specified, the URDF generation pipeline is ready.
The generated URDF file can be found here https://github.com/NUbots/NUgus.
With a URDF, file the NUgus platform can be used in various robotic simulators such as Gazebo, MuJoCo or Webots as shown below.
The generated URDF file is used for forward and inverse kinematics, dynamics, and control algorithms leveraging the tinyrobotics library which can be here NUbots