For using Owncloud and Nextcloud 
as a special remote, there are currently three choices:

* Use git-annex's builtin [[special_remotes/webdav]] support.

* Alternatively, rclone supports them
  so the [[rclone_special_remote|special_remotes/rclone]] can be used.

* Alternatively, there is a dedicated special remote,
  <https://github.com/TobiasTheViking/owncloudannex>
  (Last updated 2014)

At this time it's not clear which is better, so if you find one works
best, please comment below.
