XHProf is enabled in [https://QualityBox.us QualityBox] to <strike>create the [//{{SERVERNAME}}/ServerPerformance Server Performance] graphs.</strike> (that's regular mysql). We use XHProf for actual profiling; which is turned off by default.
== Profiling your Wiki ==
MediaWiki source has class interfaces in include/libs and uses XHProf plus custom profiling code to self analyze. When you edit a page on your wiki, you can get "Parser profiling data" at the bottom of the page which gives you important information about how "expensive" your page is. This is an important tool to allow site editors/admins know if they are doing something wrong with complex templates or function calls that would make the wiki slow.
== History ==
Originally developed at Facebook, XHProf was open sourced in Mar, 2009.