Hi, I'm running Linux in a variety of modes.
By example, in my proper desktop, I've installed two hard disks, one with Windows and other with SuSE Linux. Also is possible to install both operating systems in te same disk.
I don't use LILO, because don't like to modify the MBR, I use a boot disk to start Linux.
By other hand I've servers with only Linux running in different customers, like file servers, web servers and print servers.
Now, trying like database and mail servers.
I hope that this info could be useful for You.
Regards.