IBConsole

I had to do some research on behalf of a customer, to see how viable IBConsole (released with InterBase 6.0) would be with Firebird 2.5.2 Classic. (remember it was developed for SuperServer via the Services API only). The results were a little surprising.

1. Creating and adding users works
2. Sweep works
3. Backup works
4. Restore works (Although it does generate an access violation in the console on completion)
5. Transaction Recovery (limbo's) generates an unavailable database error.
6. Shutdown - Database shutdown completed successfully, database has been shut down
and is currently in single user mode. A gstat -h indicates that the database is in multi-user maintenace mode, so the database has been closed for maintenance and multiple connections are allowed only for SYSDBA or the database owner only.
7. Restart completes sucessfully, and gstat -h indicates that  the database is now in normal mode.
8. View Metadata generates a RDB$CHARACTER_SET not found error.
9. The SQL tool seems to work ok.

So in general - its still usable with some restrictions

Personally if you want a sraightforward tool,  I would recommend FlameRobin. Its free and it supports interactive SQL, backup/restore etc and user management. Its also cross platform so you can run it locally on Linux and MacOSX if you want.