Building and using Servo as a library has been a huge pain. I've been waiting for improvements since https://github.com/paulrouget/servoshell was abandoned
So far I’m using WebKit while I wait for libservo to be ready.
The article however is a very good explanation (as far as I can tell) of how the SpiderMonkey Javascript interpreter is linked to Servo. What I need in the first place is the layout and rendering engine, but hopefully this article will be useful for me in the future.
The embedding API used can be found at https://github.com/servo/servo/tree/master/ports/libsimplese...
I think it's a pretty low-level embedding API, so perhaps not comparable with embedding Webkit(I have no experience with that either), it does seem to do the trick.