> Popular search engines such as Google, Bing, Yahoo!, Wikipedia, Amazon, YouTube and Baidu are used to calculate the ratings.
This bit is partially inaccurate. They don't actually use Baidu, Yahoo, or YouTube because they can't parse a count of search results from those sites' search pages.
They do, however, include the number of hits for "<language> programming" on the Amazon search page... as well as on eBay, microsoft.com (i.e. Microsoft's support pages), Walmart, and Etsy.
> TIOBE Software BV was founded the 1st of October 2000 by Paul Jansen. The name TIOBE stands for “The Importance Of Being Earnest”.
> Since there are many questions about the way the TIOBE index is assembled, a special page is devoted to its definition. Basically the calculation comes down to counting hits for the search query +"<language> programming"
> Popular search engines such as Google, Bing, Yahoo!, Wikipedia, Amazon, YouTube and Baidu are used to calculate the ratings.