This is an interesting looking project, but I have to say I'm not crazy about the author's use of the name Anvil. I've owned the domain anvil.io going back several years, I've been actively using variations on the name Anvil for security related software that's in production for a period of time as well. If the authors of the project read this, please consider renaming it.
The shared language namespace is getting awfully crowded in general. If they weren't stepping on your toes, they'd likely be stepping on somebody else's.
Understood, and I'm glad to live and let live in general, but this one is too close in subject matter to my own work and may eventually lead to confusion about who's doing what. That seems like a reasonable cause for concern.