Short and sweet how I got Nehrim running on Nix. I won't go into much detail, this probably wont help some one gnu with Linux.
I use Xubuntu for games as Xfce seems to panic less and is just all around better for the stress and havoc gaming does to linux (for my system anyway). I noticed in Unity on Ubuntu resolution changes and going from desktop to game caused more problems then anything. The same was to be found in Mate and Cinnamon on Mint. Ubuntu seems to be the best base for gaming as there are a ton of games in the ubuntu store (free and otherwise) as well as many core deps installed by default or readily available in default Ubuntu repos. After testing Xfce it was apparent very quickly it was the window manager of choice for gaming, google confirmed.
Anyways, so Xubuntu 13.04 64bit
Goto settings manager, and then to software & updates under system, click over to the "additional drivers" tab and depending on your video card, choose the proper proprietary driver with the highest version number that does not say beta, or open source. Allow this to finish, if it passes error or never finishes restart and try again, if not troubleshoot your video card vs Xubuntu.
Get wine, playonlinux, and mono.. you may have to install a ppa or two I forget if all these were available by default.
For best results I went with an install from the dvd, playonlinux has a profile already for Oblivion so use it. Do the base install of Oblivion first (no library’s yet) and make sure it works. Now go back into playonlinux and update Oblivion this time choosing to install some library's. If you did not install Mono yet, you can attempt to let playonlinx do it, if it does not detect mono it will install before dotnet. I found this to be buggy, chain installing from playonlinux was a no go for me. So I installed mono, then dotnet 2.0, then its update making sure to allow everything to finish first. Sometimes playonlinux would not finish fully, and I was forced to close it. Doing so produced many odd bugs that often led to crashes. So install them all one at a time, once dotnet and its updates are installed you can move onto Oblivion updates then Nehrim.
I used playonlinux to install updates manually, I used my shivering Isle disc and the profile for it in playonlinux, then the official patch from there. Update Oblivion via playonlinux to install the patch. Make sure Oblivion works, open it once to generate an INI etc and exit out.
I again used playonlinux to again update Oblivion, but
instead of pointing to a CD or patch, I ran the Nehrim installer and thus installing Nehrim to the same virtual drive as Oblivion If you try to install Nehrim via the normal installer it will get its own new virtual drive and will fail miserably. I also placed Nehrim inside the oblivion folder just to be safe but I doubt this was necessary. I ran the Nehrim installer like a typical install where it auto copies Oblivion data to the new Nehrim directory. Once finished I was able to create a shortcut to the Nehrim Launcher from the list at the end of the install. Also using this method you wont see a new Nehrim field like Oblivion, this is normal and the result of installing Nehrim as an update to Oblivion.
Make sure the shortcut created at the end of install looks something like this for the command, If not, troubleshoot why the installer is not running correctly under Wine/playonlinux.
env WINEPREFIX="/home/YOURUSERNAME/.PlayOnLinux//wineprefix/TheElderScrolls4_Oblivion" wine C:\\Oblivion\\Nehrim\\NehrimLauncher.exe
At this point I was met with the Nehrim launcher not loading at all, I reinstalled dotnet2.0 and its updates and it poped right up. Af far as I can tell it seems to run fine, launches Nehrim like a champ. Your mileage may vary, good luck and hope it helps someone.