Native InterBase components generally work well with Firebird but as Interbase and Firebird diverge in the future this may not be the case.
3rd Party Firebird Tools & Components
High-speed, universal, direct data access Delphi components for Firebird, Interbase, MySQL, PostgreSQL, SQLite, MS SQL Server, Oracle, DB2, SQL Anywhere, dbExpress and ODBC data sources, and more, that simplifies the task of building Delphi, C++Builder and FPC database applications.
A database development tool for Interbase and Firebird. There is a free personal version and a more functional commercial version with an available trial.
IB Objects are a suite of native VCL components for direct access to Interbase or Firebird. One thing that is very cool with this package is that you can switch from the BDE to direct Interbase/Firebird connectivity in no time.
InterBase Data Access Components (IBDAC)
IBDAC from Devart is a library of components that provides access to InterBase, Firebird, and Yaffil database servers. IBDAC uses the InterBase client directly to connect to the server.