<<I'm putting together a fork of the python driver fdb with the embedded server included, with the intent of it being as easy and
use in a project as sqlite.
https://github.com/andrewleech/fdb_embedded
At the moment the setup script will download the required platforms binary release of firebird and cherry pick the required
libraries, update the dynamic library load path if required, and package it all up. If that fails it's downloads the source and
compiles firebird, before cherry picking the required libraries.
I've run into a little annoyance: none of the mac osx 2.5.4 releases appear to include the embedded library.
http://www.firebirdsql.org/en/firebird-2-5/#MacOSX
They only appear to have libfbclient.dylib. I'm pretty sure this isn't the embedded library lib renamed to client, it's too small
and it doesn't appear to work as such.
I can continue to compile from the source, but it's much faster to use the binary releases.>>

This should explain how it all works.

http://paulbeachsblog.blogspot.fr/2008/03/where-is-libfbclientdylib-on-macosx.html

Regards
Paul Beach