You guys! I just noticed that the Python language's official site, python.org, emits the 'X-Clacks-Overhead "GNU Terry Pratchett"' header. (I'm running the Chrome extension, and it's serendipitous to see which sites send it.)
The Chrome Extension: https://chrome.google.com/webstore/detail/clacks-overhead-gnu-terry/lnndfmobdoobjfcalkmfojmanbeoegab
More explanation: http://www.telegraph.co.uk/culture/books/booknews/11474455/Terry-Pratchett-will-live-on-in-the-clacks-thanks-to-fans-programming-code.html
The Chrome Extension: https://chrome.google.com/webstore/detail/clacks-overhead-gnu-terry/lnndfmobdoobjfcalkmfojmanbeoegab
More explanation: http://www.telegraph.co.uk/culture/books/booknews/11474455/Terry-Pratchett-will-live-on-in-the-clacks-thanks-to-fans-programming-code.html