Kunjika is a minimal QA/forum application built using Rust, Svelte, Postgres and Redis.
No. It is under active development and not suitable for production. It is not even alpha release. Please check github for upcoming releases. Once it is stable releases will be made on github
There is no binary release nor there is any plan to do so. The installation must be done using source code.
It is not about QA/forum only. Most web software is written using inefficient languages like PHP, Python, Java, Ruby and so on. It is an attempt to develop a web application in Rust which is very efficient and resource-friendly.
Discourse is very nice forum software but I find it bloated with features but for most use cases it should work nicely. If you want a lean/mean QA/forum only then you should choose Kunjika. The other reason is the license. Kunjika is true free software under GNU GPL and not under some other open source license.