LibC5, LibC6 and Peaceful Co-Existance

Yet Another Anonymous Coward asks this common question: "I was just wondering if it is possible to run a Linux system with both Libc-5 and Libc-6 installed simultaneously? If so, has anyone had any luck running both with a Slackware distribution? Where can I find some good HOW-TOs or more information on installing and running both Libc-5 and Libc-6 on the same system?" Yes, I know this is a FAQ, but it's something that WILL be asked. Consistently. So I'm running this one just to see how MUCH information there is and whether or not it's useful.