LOL! Keith...9i is free for personal use and for educational purposes. You can download it from the Oracle website for free mate. Its only when you build commercial applications on it that you need to pay for it. This is the same with all Oracle products.
Prajith:
TNS Protocol adapter error does not mean ur firewall is blocking it. Could you give more information w.r.t your oracle installation ? Have you installed the DB in one machine and the client in another ? Or is it all on one machine ? Also check the following in your services. Once the database is installed the Listener needs to be started check to see if it is. Also Oracle needs a static IP to be assigned to your system ? Is your system networked ? If not you need to assign some static Ip to your system. Oh and also your system name needs to be in the following format:
<host_name>.<domain_name>.<any_domain>
else Oracle will not work with host names will work only with IP's. Please read the pre-install documents carefully b4 installing 9i. Its not an easy task.