Is it possible to reverse engineer a distro?
There's a great folding one but I'd like to customise it to save having to keep doing the same few steps everytime (when I use it on new machines).
There's no gui on it so I can't see how to do it (and I'm rubbish with linux)

Surely you can just get hold of the source?
For true reverse engineering (de-compiling and the like) I've no idea about, sorry...

If it is Linux, it has to be open source, so just download the source code, no need to reverse engineer it.

You can generate a bash script, if you need to do the same sort of set-up each time...

What exactly are you trying to do? Rebrand the distro?

The program/distro is here.I can generate CD's etc using the tools on the site but would like to know how it works to customise it (thinking of producing some easy CD's to give to people to get them folding)

Gentoo is also an option...time consuming, but it should be exactly as you want it in the end.

Why don't you write a script or setup a kickstart (or equivilent) file. It's not difficult to do, but the post install scripts can be a bit time consuming to test as you have to wait for a Linux install.