I'm not sure it works to say that the multiverse contains no information,
or that running all programs entails specifying no information. If you
look at http://www.escribe.com/science/theory/m2793.html, that is Bruno's
example of a Universal Dovetailer (UD) program. It is quite a large
program, although it is written in French, and would no doubt be much
shorter if it were written in English (joke). No, actually, I think
there is some redundancy in Bruno's description; it looks like there are
some parts relating to problems with the LISP interpreter and possibly
some alternate versions of the program. But still it is pretty large.
The point of this program is to create all possible programs and to run
them in an interleaved or dovetailed fashion. That is what you need
to start with the basic ability to run a program and turn that into
the ability to run every program at once. The fact that this requires
a relatively large program suggests that there is some substantial
information content in the idea of running every program at once.