Hey, I’ve been working this last week on bringing ndb/registry over from inferno, but in a way that matches well with the rest of our ndb. 
I have two binaries, ndb/registry and ndb/regquery. ndb/registry reads from /lib/ndb/registry, which would contain a list of local services you want to register on start up. They’re in regular ndb format, and look like

service=tcp!myipaddr!1234
	auth=none label=myservice
	mtpt=/n/myservice

You can add a service by writing, `add tcp!myipaddr!1234 label myservice [mtpt mymtpt label mylabel]` to /net/registry, rm `rm tcp!myipaddr!1234`, edit, `update tcp!myipaddr!1234 label newlabel` or any other tuple. Dump will create a dump of the current registry to /lib/ndb/regdump, refresh will reload the services from the db - while keeping any that you’ve added after startup untouched. 

regquery opens and reads /net/registry, and outputs any matching service descriptions `ndb/regquery myservice`, in tuple format; or as a plumbable string (currently only srv and srvtls) with -s, and will list all services when passed `ndb/regquery all`.

eg:

ndb/regquery grid
service=tcp!myservice!1234 label=gridchat auth=none mtpt=/n/chat
[ … ] // any other matches

ndb/regquery -s grid 
srv tcp!myservice!1234 gridchat /n/chat
[ … ] // any other matches

I use this with a database containing, at the moment the 9grid list of services, but would be useful for a general index of what services exist on a given network outright, on a remote network for bookkeeping, etc.

The code is fresh, and may have bugs I haven’t caught! I’ll include the diff here, thanks!

 - halfwit