At the end of July Last.fm (our Last.fm API profile) shut off some old API calls, to the disappointment of some mashup users and developers. The company had some good reasons, but it raises the question about what developers should expect, especially from free APIs.
This week saw the widest range of APIs being used to develop mashups we’ve seen in awhile: 42 different APIs used in 7 days. Of those new apps added to our mashup directory, only a handful were map mashups, whereas most of them used more unique APIs: Google Chart API, indeed API, Livekick API, MTV API, NPR API, Tagalus API, TwitPic API, uClassify API, Vimeo API, and the Yelp API. Also, given that within the last 24 hours the highly anticipated Wolfram|Alpha search engine and structured reference went live, we did happen to see a number of semantic and linked-data APIs used this week: Reuters Calais API, DBpedia API, and Freebase API (and we’ve just added a profile for the Wolfram|Alpha API). The list below shows which APIs were used by which mashups: