What is a .udeb file?

[John O Sullivan <johno@cruithne.org>]

Hi,
Whats the difference between a .deb and a .udeb
Theres some of these in debian/pool/main/a/anna/
and also in file-retriever, main-menu, udpkg and wget-retriever
these all seem to be version 0.00x too..


thanks
johno