All big project need some replication stuff. All enteprise project needs replication. When software architect need to choose what database for his next project, look for replication and clustering/balancing.
There are some open/closed source vay to do this in FB, but there isn't NONE built-in.
Many customer's sysadmin when I propose Firebird, ask "there is a built-in replication service?"... when I say "no, but there a remany 3rdPart tools to do this..." they choose MySQL (IMHO a bad DB, but with an eye on enterpise).
Replication is THE many issue that I've found in firebird (and many our customer move from fb to mysql for this reason).
This is a big problem for today's project, do not ignore them.