The last step to complete the installation of Oracle usually requires to configure the database (users, schemas, tables etc) through the apex web page.
If your server is running locally, then all you need to do is point your browser to the following URL:
http://localhost:8080/apex (or another port if you did not use the default one, 8080).
However if you have installed Oracle on a remote server, this URL will not work.
In order to make it work, I found out that you need to enable remote HTTP connection with SQL command line :
[me@somewhere admin]# sqlplus SQL*Plus: Release 10.2.0.1.0 - Production on Sun Jul 24 21:23:20 2011 Copyright (c) 1982, 2005, Oracle. All rights reserved. Enter user-name: SYSTEM Enter password: Connected to: Oracle Database 10g Express Edition Release 10.2.0.1.0 - Production SQL> EXEC DBMS_XDB.SETLISTENERLOCALACCESS(FALSE); PL/SQL procedure successfully completed.