Very. Very popular.
DrupalGovCon, the main Drupal event in D.C. every year, is enjoying a record attedance today:
— Drupal GovCon (@drupalgovcon) July 22, 2015
In contrast, I’ve heard that several Drupal camps are down in attendance this year. Clearly D.C. is bucking that trend.
You’ve probably also heard about all the Federal government sites that are moving to Drupal, such as the newly relaunched Commerce.gov.
I was inspired to check Amazon’s sales data for Drupal 7 Explained, which is the best-selling Drupal book. This is somewhat limited data, and doesn’t include e-books, but the trends are clear.