> I am pretty new to firebird (still at the review stage) and would
> like to know if I can use a trigger to call UDF library to send a
> message via sockets to java packages running on client machines?

Yes, you can. You will need to use some static variables if you want to keep
socket open between invocations. Also note that your UDF can (and most
likely will) be called from multiple threads if you use SuperServer, you
have to take care of multithreading issues.

> If not, can I send events to different packages (either in C++ or
> java) residing on different
> machine to the database?

Yes (only in C++ though), if they are connected to the database and are
subscribed on your events.

> I have read something about POST_EVENT and understand the concept behind
> it but do not understand how in reality I can get them working?

Events are not supported in JayBird yet. For Delphi examples see InterBase
"Developers Guide" (can be found on ibphoenix.com). For C/C++ examples see
InterBase "API Guide".

> Is there an example I can download?

C code you can find in examples/ directory of your Firebird installation
(see api16.c file)

> Does the Firebird ODBC or JODBC driver support the event facility?

JDBC driver does not support it. I suspect that ODBC driver does not support
it too, but better ask in Firebird-Support group.

Roman