X.Org Server Bids Farewell To Autotools
X.Org Server is now all-in on using the Meson build system support that is considered quite mature at this point.
Removing Autotools support from the codebase lightened up the tree by over six thousand lines.
Plus Meson has better cross-platform support, much more modern and easier to maintain, and goes along with the overall trend of open-source projects transitioning over to Meson as the dominant build system of recent years.
X.Org Server 21.1 is the last series to have Autotools support -- that is if/when there is ultimately a next major X.Org Server release given it took three years for v21.1 before someone stepped up to manage the release and most Linux distributions transitioning to Wayland-based sessions.