Here’s how to install and use NFO viewer in Ubuntu 11.10 Oneiric Ocelot:
1. Issue the following command at the terminal –
sudo apt-get install nfoview
2. After the installation is complete, type ‘nfoview’ in the Unity dash and click ‘NFO Viewer’ to start the application.
3. Now, to open a NFO file, click on ‘File>Open’, browse and select your NFO file and then click ‘Open’ to view it.