[borispavlovic]

There's a viable privately hosted alternative with Atlassian's "Questions for Confluence" (https://www.atlassian.com/software/confluence/questions)

[jiaweihli]

I looked into this briefly in the past, but it didn't seem viable.

Reviews complain about bugginess and pricing: https://marketplace.atlassian.com/plugins/com.atlassian.conf...

And active development stopped in early 2016: https://marketplace.atlassian.com/plugins/com.atlassian.conf...