The nano-node project brings in C++ nano-pow-server as a git submodule and, during the release process, it builds it and adds it to the nano-node docker.
https://github.com/nanocurrency/nano-pow-server.git

The nano-pow-server is both an independent project and a submodule of nano-node.
That is a complexity that seems unnecessary.

Additionally, there is an alternative pow server called nano-work-server and written in Rust, which seems to have superseded nano-pow-server.
https://github.com/nanocurrency/nano-pow-server.git

In the interests of reducing unnecessary complexity, we will be removing nano-pow-server from nano GitHub and from nano docker releases.