> The idea was to have a syntax with a grammar -> XML. We wanted a
> single file to describe everything and we didn't want to embedd one
> format in another.
If you are describing package dependencies, I have found that meta-packages solve that problem neatly. And the result is compatible out-of-the-box with the rest of Debian.
If you are describing the process to translate a directory into a filesystem image, shell scripts and guestfish have worked well for me. And, they tend to mirror the instructions of a HOWTO, so they're self-documenting.
I'm not familiar with ELBE, but I'm kinda with the naysayers on this one at the moment. I'm a heavy, heavy debootstrap et. al user, and I've found that the basic tools are pretty darned good already. The idea of adding XML to the mix to drive them seems pretty overkill.
b.g.