HypeCharts are created tapping on over a hundred different resources, including download sites, software projects, job boards, forums, web pages and more. They try to offer an insight about current industry trends, showing which technologies are really being used in practice, and which ones are only making noise.
You can run your own query, which - in order to reduce response time - uses only a subset of the predefined resources, producing a similar but less precise result. If you think a particular comparison would be interesting to the community, contact me to asking to add it to the list of automatically generated queries. The query must consist of a set of comma-separated terms. For example, if you want the HypeChart of Java vs PHP, you'd enter "Java,PHP".