Read HTML is my API by Aaron PareckiAaron Parecki (Aaron Parecki)
In August 2012, I wrote a quick script to stream front-page Hackernews stories to an IRC channel on Freenode (##hackernews in case you're interested) so that I could quickly glance at popular stories there instead of needing to load Hackernews. Since IRC is my feed reader, I've always tried to pipe as much there as possible.
Very smart and reminiscent of some of the stuff Drew McLellan and Jeremy Keith were doing almost a decade before. There is a lot more power in microformats that most web developers give them credit for. Aaron has a great example and use-case.

My favorite part here:

So in 2.5 years of parsing the HTML, I never had any problems. In 2 days of parsing the JSON API, I hit a glitch where all the stories were empty.
Since more people and programs see the HTML than use the API, the HTML ends up being more reliable.