I'm Colin's "wizard" so let me fill in a few more details.
The system had a single IDE drive which contained both Linux and the Oracle executables, and then a RAID setup for everything else. The internal drive died, and there were no backups. He had a local sys admin put Linux back together and we were able to recover Oracle (8.1.6) from his development system, and the data files are on the RAID so we still have those, but the control files are lost.
In addition, it seems there were no database dumps being performed and/or we have lost those too. I'm not exactly sure. Colin and I are both sure that the dumps were happening a couple of years ago (because I set them up), but somewhere along the way they seem to have stopped. There have been several admins working on thes system over time, so we don't know exactly who has done what.
Anyway, the only way to recover his user's data is to get Oracle up and running. I was working on it and having trouble with it not finding a library that is plainly there, when I realized that the control files were missing. I've never done this type of recovery before, and I told him that he'd be better off hiring someone who really knows how to do this than waiting for me to figure it out.
I know you're all cringing by now... let me just say that I've been helping Colin out over the last few years as a favor, just stepping in when things get sticky. This should not be taken as an example of how furfly runs their servers! :)