- is ad ridden,
- tracks the bejeezus out of you,
- looks a bit sketchy in some places,
- has a lot of junk you have to wade through before getting to the interesting part,
- and of course is not community-driven the way a Github list is.
On the other hand, when they do have a summary - see e.g. some API I picked up at random[0] - it's significantly better and more useful than what is on the Github list.
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- has plenty of ads (vs. no ads on GitHub),
- tracks the bejeezus out of you,
- the site itself looks more like a news site than catalogue (possibly because it is also a news site about APIs),
- it's not so community driven compared to a GitHub list (OTOH, it seems much more organized),
- it's heavy (resource-wise) compared to GitHub,
- but, it has much better summaries of APIs and links to plenty of related resources for each,
- and it has much more APIs than the Github list.
So please don't be discouraged by my comments; if you're into APIs, check the PW site out and form your own opinion.