Database Support
I don't know much about firebird -- will have to look into it.  Currently, peewee's internal db calls rely on the driver supporting the python db-api 2.0.  It looks like kinterbasdb supports this, so integration should be really easy.  I was thinking personally that the next driver i'd like to look at is [apsw](http://apidoc.apsw.googlecode.com/hg/index.html), which provides much richer support for sqlite than the sqlite3 driver (virtual tables, etc).  If you want to see firebird, i'd suggest taking a crack at it yourself, the implementation should be simple - take a look at the code.

You will need to implement at the very least:
- an adapter class, which handles connecting to the database (here is [mysql](https://github.com/coleifer/peewee/blob/master/peewee.py#L224))
- a database class that uses the given adapter (here is [mysql](https://github.com/coleifer/peewee/blob/master/peewee.py#L537))

It is unlikely i'll be adding firebird support any time soon without learning a bit more about it and its advantages over, say, postgres mysql or sqlite which seem to run the gamut from prototype to large-scale production, but if you're inclined i'd be happy to merge in your changes if you write an implementation.
 I've written some docs on writing a database backend:

http://peewee.readthedocs.org/en/latest/peewee/database.html#writing-a-database-driver

What is next database that will be supported by peewe? Any plan for firebird? 
For prototyping sqlite is enough, but for portable database in production embedded firebird could give more power...
