MediaWiki 1.28 introduced an optional pingback feature [0][1]. This feature is disabled by default.
The pingback feature allows MediaWiki anonymously to report back information about its installation to help developers: the MediaWiki version, database type, PHP version, operating system, system type (32-bit or 64-bit), machine hardware, web server software, and memory limit.
Aggregate pingback data collected since March 2017 is now viewable at https://pingback.wmflabs.org in graphical and tabular form. While this data only includes sites that opted in to data collection, it shows over 40,000 unique installations of MediaWiki in the last year in a variety of different configurations.
Enjoy exploring the aggregate data!
[0] https://www.mediawiki.org/wiki/Manual:$wgPingback [1] https://wikimediafoundation.org/wiki/MediaWiki_Pingback_Privacy_Statement
______________________________ Cindy Cicalese Product Manager, MediaWiki Platform Wikimedia Foundation