In this document we list all the pieces of code included by ORB-SLAM3 and linked libraries which are not property of the authors of ORB-SLAM3.
#####Code in **src** and **include** folders
* *ORBextractor.cc*.
This is a modified version of orb.cpp of OpenCV library. The original code is BSD licensed.
* *PnPsolver.h, PnPsolver.cc*.
This is a modified version of the epnp.h and epnp.cc of Vincent Lepetit.
This code can be found in popular BSD licensed computer vision libraries as [OpenCV](https://github.com/Itseez/opencv/blob/master/modules/calib3d/src/epnp.cpp) and [OpenGV](https://github.com/laurentkneip/opengv/blob/master/src/absolute_pose/modules/Epnp.cpp). The original code is FreeBSD.
* *MLPnPsolver.h, MLPnPsolver.cc*.
This is a modified version of the MLPnP of Steffen Urban from [here](https://github.com/urbste/opengv).
The original code is BSD licensed.
* Function *ORBmatcher::DescriptorDistance* in *ORBmatcher.cc*.
The code is from: http://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetParallel.
The code is in the public domain.
#####Code in Thirdparty folder
* All code in **DBoW2** folder.
This is a modified version of [DBoW2](https://github.com/dorian3d/DBoW2) and [DLib](https://github.com/dorian3d/DLib) library. All files included are BSD licensed.
* All code in **g2o** folder.
This is a modified version of [g2o](https://github.com/RainerKuemmerle/g2o). All files included are BSD licensed.
#####Library dependencies
* **Pangolin (visualization and user interface)**.
For versions greater than 3.1.1 is MPL2, earlier versions are LGPLv3.
* **ROS (Optional, only if you build Examples/ROS)**.
BSD license. In the manifest.xml the only declared package dependencies are roscpp, tf, sensor_msgs, image_transport, cv_bridge, which are all BSD licensed.
