Nice, work! One minor gripe though - every tag I've tried (Java, C, C++, Python, PHP, Haskell, Scala) has had a dropoff in the number of questions asked over the past couple of months. This suggests that there may be some seasonality in the number of questions asked (or at least, a more general dropoff in questions asked over the past couple of months).
I think the results would be more meaningful if they either corrected for the seasonality, or presented the results as relative to the total number of questions asked.
Ran a sample query of "Rails" vs. "Django" on Chrome 27 on 64-bit Windows 7 Professional, but unfortunately all I get is "Too many queries are running, you may only run 2 queries at a time."
I think the results would be more meaningful if they either corrected for the seasonality, or presented the results as relative to the total number of questions asked.