[impoverished]

Couldn't you accomplish this with djbdns' dnsrewrite or pdns_recursor's lua scripting?

Why anyone would want to write DNS server (=something that needs to be very fast) in Javascript is beyond my comprehension. The ASCII art is probably better work than the DNS server.

[j-kidd]

Or unbound's python scripting. Or if GeoScaling slightly improves its excellent smart subdomain service, 2 lines of php script.