[uludag]

Just to name a few, https://github.com/legalnonsense/elgantt/, https://github.com/elsatch/org-timeline-viewer, https://orgmode.org/worg/org-tutorials/org-taskjuggler.html . Org-mode users and things like this seem to be like moths and a fire. I'm always surprised by the sheer amount of packages written for org-mode, a package itself of a rather niche piece of software.