> reverse engineering existing clients and servers by inspecting their requests and responses.

What a strange process... why not read the source code of an open source working library (easy to test, run a client made by someone else on its server, and vice versa) in a language close to the target?

Why not use then those tests as a way to verify your own work after?

FWIW I'm using WebDAV, both with clients and with my own self hosted servers, on a daily basis and... it works.