ROS Mapping - so much to explore

After putting “Humble” ROSbot Dave in stasis for about a year, @este has revived my interest in ROS and all the mysteries are flooding back.

When I last visited the ROS 2 Humble Hawksbill “pre-built image”, it was mapping despite my total lack of understanding of how.

While wandering today I found this:

Makes me wonder what package my “Humble” Dave was using.