This site now generates a JSON data dump of each article. The URL of the JSON data is the same as the article's URL, with the "php" replaced by "json". http://la.indymedia.org/news/2013/03/258838.json
This is basically a dump of our internal data. Nothing has been omitted at this time, though in the future some fields might be lost. So this non-API may change. However, given our past history with failure to keep up with software changes, odds are this ad-hoc dump is as good as any set-in-stone API out there, because the big APIs change every couple years. We've outlasted a lot of other sites, and are slow to change.
If you do develop a JS client (or any client really), THANK YOU!
Remember, however, that you can't put ads on the stories or in the client, because the articles are only allowed to be reused non-commercially (unless you get an agreement with the original author). Our standard agreement is an article is free for noncommercial use by us and by noncommercial sites, but copyright belongs to the author. (The exception being Fair Use, of course. Also, it's unclear what status RSS feed data has. I've assumed RSS data is reusable for anything without restrictions.)