If you want to us Interbase, as compared to Firebird, the licensing goes
as follows:

- Open Source Edition - no user licensing, so no licensed limit

- "Certified" builds -- for Internet (only) access, you need to purchase
appropriate internet license

- "Certified" builds -- for internal/wan access you need to purchase an
appropriate number of user licenses. These licenses are in *addition*
to the internet license.

- Firebird - no user licensing, so no licensed limit


Sean