MobiPocket has not said anything about such code, but it is now
available in several programs (notably Calibre, a very popular ebook
format shifting package which has a Python implementation of the
decompression scheme) and MobiPocket has not acted against any of the
sites distributing the code or its authors (they have acted in the
past against sites and individuals who posted derivatives of
MobiPocket copyrighted software). Note that this is definitely not a
DRM scheme, for example the mobigen.exe MOBI generator has separate
switches for DRM and compression and this is a compression option.
Also, there are DRM-free MOBI ebooks using this compression scheme.
So I think the only remaining question is whether MobiPocket has
patents for the compression scheme. If they have patents, they have
not acted against the existing distributors of decompression
software. Also, the decompression scheme would need to be patented
and this is much less likely to contain new methods than the
compression scheme. Since they are keeping the existence of any
patents secret, it is my understanding that the initial remedy would
simply be the removal of the offending software from "sale" if they
ever gave notification of the patent.
Alan.