My ZDNet colleague Steven J. Vaughan-Nichols discovered an amazing resource last week.

The United States government runs a customized version of Google Analytics that collects information from visitors to 3800 total websites run by government agencies. As part of what it calls the Digital Analytics Program (DAP), the government helpfully publishes snapshots of the data, released to the public domain on the analytics.usa.gov website, which is powered by open source software.

Steven wrote two interesting articles based on that data, offering a general overview of how people use operating systemsand browsers in the United States.

What I love about this data is that we finally have statistically meaningful details about which technologies people are using in the United States today. The database is enormous, and it should be broadly representative of the U.S. population, with a mix of consumers and businesses represented. (The data reported here is not strictly limited to the United States, of course. People from foreign countries occasionally need information from the United States government. But for the sake of this article one can consider the data to be an accurate snapshot of the U.S.)

The two most popular independent analytics services, StatCounter and Net Applications, have become increasingly unreliable and error-prone. The U.S. government data offers a much more reliable and consistent sample set, and the Google Analytics platform underlying it is the gold standard for measuring web traffic.

I decided to download the last three months of data (representing more than 1.4 billion individual visits) and zero in on some questions that I’ve been following for years. The results apply only to the U.S., of course. Other countries might show very different results, and a global picture would probably differ considerably as well.

The desktop PC is alive and well

The first thing to note is that people still turn primarily to desktop PCs when they need information from the government. Here’s the breakdown from those 1.4 billion visits:

And among those desktop visitors, the PC is still dominant, with Macs accounting for roughly 1 in every 7 visits. (Sorry, I couldn’t resist choosing the very appropriate Pac-Man colors for this pie chart.)

It’s certainly a safe assumption that the United States is one of Apple’s strongest markets for Macs. A more global breakdown would most likely shift a few points to the Windows slice, which aligns nicely with the consensus that Windows has about a 90 percent share of the global market for conventional PCs.

(And a side note: Visits from devices running Linux account for a number equal to almost exactly 1 percent of all desktop traffic, although it appears that the government lumps Linux in with the mobile category for some reason.)

I was surprised at how small the share is for tablets, but that’s in line with recent figures showing a slowdown in tablet sales.

Many of the summary pages at the government’s public analytics portal mash those categories together, making it difficult to see some trends. So I separated out the numbers for desktop visits to get a more detailed view.

Windows 7 is insanely popular

The five-year-old Windows 7 is the clear winner on the desktop, with Windows 8.1 a distant second (but still larger than the entire Mac installed base). This chart shows the versions in use on all Windows PCs

The percentage of visitors clinging to the unsupported Windows XP is still higher than I suspect Microsoft would like, at 5.8 percent. Windows Vista is fading faster, with only 3.9 percent of visitors sticking with it…

Read the rest of this Ed Bott/ZD Net article here.