I've only briefly tested this (so far). rdiff-backup on WSL (Windows Subsystem for Linux) can be used to backup Windows files to a rdiffweb server. I was expecting that it would work, but I wanted to test it as I haven't seen any references to WSL in the documentation or this group.
On the WSL instance I was running
rdiff-backup.x86_64 2.2.6-2.fc37
and on the server
rdiff-backup/jammy,now 2.0.5-3build1 amd64 [installed,automatic]
rdiffweb/jammy,now 2.8.8+deb22.04 all [installed]
Thanks!