An explanation of the strange dip in Java popularity in 2004:<p>Q: What happened to Java in April 2004? Did you change your methodology?<p>A: No, we did not change our methodology at that time. Google changed its methodology. They performed a general sweep action to get rid of all kinds of web sites that had been pushed up. As a consequence, there was a huge drop for languages such as Java and C++. In order to minimize such fluctuations in the future, we added two more search engines (MSN and Yahoo) a few months after this incident.<p><a href="http://www.tiobe.com/index.php/content/paperinfo/tpci/index.html" rel="nofollow">http://www.tiobe.com/index.php/content/paperinfo/tpci/index....</a>
Given the huge margins of error in their methodology, the differences seem too small to justify a headline like that. They aggregated all sorts of noisy data sources (one even being the number of hits for a web search!), and found that C has pulled ahead of Java by... 0.007%. Whatever MOE you want to put on their figures, I'd be willing to be it should be more than 0.007%... probably >1%.