Is there a map repository somewhere standard?
If so you could build a plugin on both platforms to create a pub-sub relationship and automatically post a new Topic for each new map submitted to the repo.
See: PubSubHubbub Core 0.4 -- Working Draft
I’ve built such a thing previously, but I’m afraid it’s not OS.
This would require a reasonable amount of work (and buy-in if you don’t own the map repo) but is very pragmatic.