My question was resolved.
Thank you very much!!

Thank you for the answer.
I read "http://mythruna.com/forum/index.php?topic=1200.0", and I downloaded "mythruna for windows" and "mythruna for Linux".
I couldn't understand the sentence "For MAC, do the same thing, but the server ....". Although my Os is Windows8, is there need to do this sentence: making Run.bat.
I tried to make Run.bat and run in folder of "mythruna for Linux", but nothing happened.

Hello.
Although I want to build my own server, I didn't understand the way to build server.
I can open router's port. So please tell me how to build server after open router's port, and how my fiends to join my server.
I'm japanese so I may make mistake in using English.　Any help would be appreciated.