As some of you may or may not know I was once involved in the project know as OblivionOnline. It was fun while it lasted, but the latest planned version (0.5) which would be the first one to have some actually game play and not just being a proof of concept was sadly never released. Hell, it even had Fallout 3 support planned. However was quite a lot of internal conflict in the team, and the source code was ripped off and re branded at least twice. In the end the only guy that actually made the coding got tired of it all and decided to do better things with his life. Although not officially dead yet, do not expect any new version to come out in a long long time.
Now, why am I writing this? Well, for a number of reasons. The OblibionOnline site will not live on forever, and since the project was relatively unknown I do not want what little that came out of it to get lost like the Morrowind online mod (good luck finding that). So without further ado, here are the two semi-usable versions and instructions on how to play them.
0.4.5 and 0.4.8 are the two current versions of the mod. 0.4.5 has some decent character synchronization and some bugged combat that works sometimes. 0.4.8 was a complete rewrite and had an in-game chat box with a few options and NPC synchronization. Though this version suffers from some major lag and is really bugged. It is not even worth trying.
So if you just want to play you need to download the 0.4.5 "litos" repack and follow these easy instructions:
First of all, you will need to have Oblivion installed and patched with the last official patch. Extract consoleserver.exe and realmlist.wth into the oblivion root directory (next to oblivion.exe) Do the same with the content of the packed \obse\ folder so that all the files beginning with "obse_" are in the same directory as oblivion.exe. The contents of the packed \data\ folder goes into the \data\ folder in the oblivion directory. (Note: This version of OblivionOnline will only work with the 14th version of OBSE, do not attempt to use a never one, it will crash)
Now, edit the realmlist.wth file with Notepad and put in your IP. Make sure you do not change the port or the number "1" at the first line.
Finally, you will need to forward port 41805. There are plenty of tutorials on how to forward ports, just Google it.
Now, simply launch ConsoleServer.exe and in the Oblivion launcher, tick OblivionOnline.esp. Go to the First Edition bookstore in Imperial City and talk to the new NPC standing there. If all goes well you will have connected to your own server. Check the games console, there shouldn't be any errors.
For the second player to join, he will have to repeat all the above, except starting the server. And in the realmlist.wth file he will enter your IP.
Here is a really old video that shows off version 0.0.2 with a player running around for a minute. Version 0.4.5 is of course a bit better.