For how to make it appear in Xcode, read the next post, Client connections.

For how to make it appear in Console, first read the section on ASL_KEY_FACILITY, then read Client connections (you can set the default facility of every message with a client connection).

Reading the entire series is a good idea in general. ☺

Using XCode 3.0 (Leopard) I coded:
asl_log(NULL, NULL, 1, "TESTING ASL-LOG:%s", "asl-log test");
but do not see anything resulting from it.
Neither in the XCode console, nor in the Console app. Why not?
Am I doing something wrong?