Here's an XSL file, "nlm2mods", for converting journal articles stored in the NLM's Journal Publishing XML format into MODS XML. This will be useful, in conjunction with bibutils, to allow export of bibliographic metadata from journals that produce articles in the NLM format.
If you find this useful and make any improvements (it's quite basic at the moment), please let me know.
Update: I've put this on the server here as a web service. To produce bibliographic metadata from an XML file in the NLM Journal Publishing format, call this URL:
http://www.hubmed.org/export/xsl.cgi with the parameters
nlm (URL for the NLM XML file) and
format (output format: one of 'mods', 'bibtex', 'ris' or 'refer'). Here's an example.