Last.fm besides being one of the most popular online radio and music communities, also has one of the most popular online music APIs. Possibly the most popular. Each month we continue to see a variety of new music-themed mashups added to our directory built on the Last.fm API. In the first three weeks of this month alone there have been 5 more Last.fm mashups added. That means that out of 231 music mashups at least 84 use the Last.fm API. And not that developers don't have other options given that there are 44 music APIs to choose from.