Call Me Al

As an update to my earlier post, here is a simpler solution for launching links in Linux when Firebird is already open:

#!/bin/bash
/path/MozillaFirebird -remote "openURL($@, new-tab)" || 
        exec /path/MozillaFirebird "$@";

This is Bug 177996. Be aware that you cannot launch a second profile at the same time if you use this workaround

There is also a maintained MNG extension for Firebird. The database will be updated to the new link when someone gets around to it.