Linux Terminal Server Project helps in netbooting LAN clients from a single template installation that resides in a virtual machine image or a chroot on the LTSP server, or the server root (/, chrootless). This way maintaining tens or hundreds of diskless clients is as easy as maintaining a single PC.
LTSP has been redesigned and rewritten from scratch in 2019 by alkisg in order to support new technologies like systemd, updated desktop environments, Wayland, UEFI etc. Only the new version is actively developed, while the old one is now called LTSP5 and is in minimal maintenance mode. Here is a review of the new sites, followed by the LTSP5 sites that are being deprecated:
These sites are maintained by LTSP developers. That usually means “only basic documentation/feedback, but accurate and well maintained”.
These sites are maintained by the LTSP community, with occasional help from LTSP developers. That could mean “more documentation/feedback including unusual scenarios, but some information might not be very accurate or up to date”.
Resources for the old LTSP5; they will become obsolete when users switch to the new LTSP.