well, the mwpl does not explicitly make linking a derivation, so it does have the 'link-with-non-free-modifications' loophole a la npl. however, i do like the fact (at least i do when i'm wearing my gpl-liking hat, which is sometimes) that it requires contributors to licence their modifications under the mwpl, *and* provide licence to use the code under any applicable patents they own (sadly, it doesn't require a licence to use further improvements under the patent, but one can't be perfect, and it *is* a good bonus). i also like the requirement that you provide information about any applicable ip claims you know about when distributing it; the 'that you know about' is important and keeps it dfsg-free, imo.
they are a bit shaky in determining adequate means of distribution, for the source and especially the LEGAL notice ("other steps, such as notifying appropriate mailing lists or newsgroups"... pretty vague), but nothing too bad, i don't think. --phouchg "Reasoning is partly insane" --Rush, "Anagram (for Mongo)" PGP 5.0 key (0xE024447449) at http://cif.rochester.edu/~phouchg/pgpkey.txt