Facebook releases internal C++ libraries as open source
arstechnica.com/information-technology/2012/06/facebook-releases-internal-c-libraries-as-open-source
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
The assortment of frameworks is collectively called Folly, the Facebook Open Source Library. Its individual components support a diverse spectrum of capabilities, ranging from general-purpose programming functionality to more specialized pieces that are designed to help developers wring extra performance out of complex applications.