MODS was an attempt to mostly-but-not-entirely-roundtrippably represent 
data in MARC in a format that's more 'normal' XML, without packed bytes 
in elements, with element names that are more or less self-documenting, 
etc.  It's caught on even less than MARCXML though, so if you find 
MARCXML under-adopted (I disagree), you won't like MODS.

Personally I think MODS is kind of the worst of both worlds. The only 
reason to stick with something that looks anything like MARC is to be 
round-trippable with legacy MARC, which MODS is not.  But if you're 
going to give that up, you really want more improvements than MODS 
supplies, it's still got a lot of the unfortunate legacy of MARC in it.

Nate Vack wrote:
> On Mon, Oct 25, 2010 at 2:09 PM, Tim Spalding <[log in to unmask]> wrote:
>   
>> - XML is self-describing, binary is not.
>>
>> Not to quibble, but that's only in a theoretical sense here. Something
>> like Amazon XML is truly self-describing. MARCXML is self-obfuscating.
>> At least MARC records kinda imitate catalog cards.
>>     
>
> Yeah -- this is kinda the source of my confusion. In the case of the
> files I'm reading, it's not that it's hard to find out where the
> nMeasurement field lives (it's six short ints starting at offset 64),
> but what the field means, and whether or not I care about it.
>
> Switching to an XML format doesn't help with that at all.
>
> WRT character encoding issues and validation: if MARC and MARCXML are
> round-trippable, a solution in one environment is equivalent to a
> solution in the other.
>
> And I think we've all seen plenty of unvalidated, badly-formed XML,
> and plenty with Character Encoding Problems™ ;-)
>
> Thanks for the input!
> -Nate
>
>