The gflags package contains a C++ library that implements commandline flags processing. It includes built-in support for standard types such as string and the ability to define flags in the source file in which they are used. Online documentation available at:
Mastering ROS for Robotics Programming - Second-Edition, published by Packt
Detailed comments for ORB-SLAM2 with trouble-shooting, key formula derivation, and diagrammatic drawing
Pangolin is a lightweight portable rapid development library for managing OpenGL display / interaction and abstracting video input.
Fast LOAM: Fast and Optimized Lidar Odometry And Mapping for indoor/outdoor localization (Lidar SLAM)