Although MSSQL is not officially supported,
Are there any future plans to support it?
This can be crucial for corporate customers.
Thank you for clarifying this important question for us.
Hello, there’s no plan. See https://dev.xwiki.org/xwiki/bin/view/Community/SupportStrategy/DatabaseSupportStrategy
The following databases are not officially supported. XWiki may work with them, completely or partly. We don’t constantly test against it, we don’t ensure that new features work on them. However whenever someone raises an issue on JIRA about them and it’s easy to fix (or if someone provides a patch) then we fix it.