The last real ORBSLAM2 commit, i.e. code change, to Raul Mur-Artal's ORBSLAM2 repository was in January 2017.

No project is ever perfect and complete, especially in this fast-moving field, so I assume this means the ORB_SLAM2 repo is essentially gradually going stale. It looks like the development was done for the IEEE paper ORB-SLAM2: An Open-Source SLAM System for Monocular, Stereo, and RGB-D Cameras and I guess, now that paper is out, that the authors have moved onto other things.

ORBSLAM2 has a huge number of forks (1,722 currently), does anyone know if any of them represent a likely home for the long-lived ongoing development of ORBSLAM2? I guess a lot of people have an interest in seeing this happen, e.g. the ETH Autonomous Systems Lab that maintains orbslam2_ros and the catkinized version of ORB_SLAM2.