If you have it set up so that it all runs from the server, you must run net80 config to set up a tnsname for the database. At this point you can give it any alias you want, as long as it points to the correct server and sid. If you are doing ANY of the procressing client side, than you will need to have Oracle client on each workstation.
By the way, I just finaly got Oracle's developer server to run, no client software needed, and existing Oracle developer forms execute with no modification.