CDlinux 0.6.x and 0.9.x is binary compatible with Slackware 11. You can use Slackware 11 packages in CDlinux. If you want to compile your own packages, you can also use Slackware 11. Note, you should also add all the dependencies of your packages to CDlinux too.

CDlinux 0.4.x is binary compatible with Slackware 8.1. You can compile your own packages for CDlinux 0.4.x with Slackware 8.1, or use packages from Slackware 8.1 directly. Again, you need to add all the dependencies too.