Developer discussion for Creative Commons technology and tools

[Jason Kivlighn <jkivlighn AT gmail.com>]

I'm looking through Subversion for modules relating to metadata and came
across these three: xmp, cctagutils, and cli_tools.  These all appear to
do some subset of what the embedding/extracting aspect of liblicense[1]
does, so I want to pose the question:  Can we work towards removing them
in favor of liblicense?

 * xmp - An embedding GUI frontend for liblicense could replace
pdf_license_manager
             PHP bindings for liblicense could replace jpeg-php,
although we'd have to figure out handling of arbitrary metadata in
liblicense.
 * cctagutils - Liblicense can embed licenses in all formats supported
by cctagutils.  The liblicense python bindings make it an easy
replacement for cctagutils.  Liblicense doesn't do other metadata that
cctagutils handles, but it already links against the libraries that
would easily allow this.
 * cli_tools - 1) I couldn't get it to run (name 'validateOptions' is
not defined) and 2) from the README, it looks like it extracts/embeds
licenses from MP3's.  That's exactly what liblicense can do, except in
it's in python.  Again, the liblicense python bindings cover that.

On a larger scale, consolidating metadata handling could really help
towards clear metadata standards and easy metadata embedding relating to
licenses.  During my research for a Google SoC project, I came across
several CC/non-CC applications/libraries dealing with metadata and
frankly didn't know what to make of them.  I wondered if what I was
looking at was obsolete or an out-dated way of handling metadata.  The
tools' methods of handling metadata I found and what I found on the Wiki
contradicted one-another.  Several tools worked at one point, and looks
like they have since become neglected and broken.

I think that consolidating license embedding and extracting into
liblicense can help towards a definitive metadata standard for
licenses.  CC could point to liblicense and say: "This is how licenses
should be embedded in format X".  Already, Liblicense reads and writes
licenses to avi, mov, jpeg, png, tiff, wav, vorbis, mp3, flac, musepack,
svg, pdf, and smil.

Liblicense is portable.  It will (eventually) work on all OS'es; the
libraries required for embedding/extracting licenses are all
platform-independent.  And it's in C so bindings, IMHO, are trivial to
write. (I hear we've just picked up Ruby bindings)

Liblicense doesn't yet do everything it needs to for my proposal, but
I've got (at least) the rest of the summer to work on it.  Let me know
what needs to be done, and I can get on it.  And if anyone else would
like to jump in, liblicense is in an early state, making it a great time
to step up and get involved.

Cheers,
Jason

[1] http://wiki.creativecommons.org/Liblicense