Most of the documentation is a snapshot of the old Namesys site (archive.org, 2007-09-29).
There was also a Reiser4 Wiki (archive.org, 2007-07-06) once on pub.namesys.com.
Reiser4 development appears to have stalled and ReiserFS is deprecated and scheduled to be removed from mainline Linux in 2025.
Pages that link to "File:Grub-0.97-libaal-1.0.5-reiser4progs-1.0.5.patch.txt"
From Reiser4 FS Wiki