Interesting Stats... Browser and OS choice of my readers

So, I noticed blogger.com autodetects OS and Browser of viewers to the blog. I then thought... "Wow, this is interesting..." and decided to publish. I wonder how they run the detection? User Agent? Fascinating stuff, especially the variety xD Pageviews by Browsers

Firefox 189 (43%) Chrome 138 (31%) Internet Explorer 42 (9%) Opera 31 (7%) Konqueror 12 (2%) Safari 10 (2%) Mobile 7 (1%) Mobile Safari 4 (<1%) Comodo_Dragon 1 (<1%)

Pageviews by Operating Systems

Windows 262 (61%) Linux 95 (22%) Macintosh 27 (6%) Ubuntu 21 (4%) iPhone 8 (1%) Other Unix 6 (1%) Android 5 (1%) iPad 2 (<1%)