The marc-in-json<http://dilettantes.code4lib.org/blog/2010/09/a-proposal-to-serialize-marc-in-json/>format is, as you might expect, a JSON serialization for MARC. A JSON serialization for MARC is potentially useful in the same places where MARC-XML would be useful (long records, utility of human-readable records, etc.) without what many perceive to be the relative pain of working with XML vs JSON.
It's currently supported across several implementations: - ruby's *marc* gem - php's *File_MARC* - java's *marc4j* - python's *pymarc* There wasn't one for perl, so I wrote one :-) MARC::File::MiJ<http://search.cpan.org/~gmcharlt/MARC-File-MiJ-0.01/lib/MARC/File/MiJ.pm>is a perl module that allows MARC::Record to encode/decode marc-in-json. It also supplies a handler to MARC::File/MARC::Batch that will read marc-in-json records from a newline-delimited-json (ndj) file (where each line is a JSON object without unescaped newlines, ending with a newline). marc-in-json encoding/decoding tends to be pretty fast<http://robotlibrarian.billdueber.com/sizespeed-of-various-marc-serializations-using-ruby-marc/>, since json parsers tend to be pretty fast, and uncompressed filesizes occupy a middle-ground between binary marc and marc-xml. A sample file of about 18k marc records looks like this: 31M topics.mrc 56M topics.ndj (newline-delimited JSON) 93M topics.xml 8.9M topics.mrc.gz 7.9M topics.ndj.gz 8.7M topics.xml.gz ...so obviously it compresses pretty well, too. I can take generic questions; bugs should go to https://rt.cpan.org/Public/Bug/Report.html?Queue=MARC-File-MiJ [ Note that there are many other possible JSON serializations for MARC<http://jakoblog.de/2011/04/13/mapping-bibliographic-record-subfields-to-json/>, including the (incompatible) one implemented in the MARC::File::JSON<http://search.cpan.org/~cfouts/MARC-File-JSON-0.002/lib/MARC/File/JSON.pm>module] -- Bill Dueber Library Systems Programmer University of Michigan Library