Possibly I am missing something, but is it different from, say, nginx's `root /var/www/$http_host`? The description sounds as if a whole web server is written for that feature.
ha, 1) nginx is a webserver not a development ecosystem, and 2) You'll probably find if you look that many people using Node are also using nginx, because they are complementary, not exclusionary, and 3) open your eyes and reality a bit