I spent quite a bit of time on it last year, a few weeks of full-time work or so, but haven't spent anything on it for quite a while. There's a bunch of things I'd like to do so I'll probably spend another burst of effort in the future.

It's kind of an annoying project to work on because everything is platform-dependent (and at times fickle) so you can't "just" run "go test ./..." but really do need to test it on all platforms. BSD and illumos aren't too much trouble, macOS is already rather painful (slow), and the experience of running Windows is not something I'm able to describe using only polite terms.