  GitHub hosts hundreds of millions of code repositories written in hundreds of
different programming languages. In addition to its hosting services, GitHub
provides data and insights into code, such as vulnerability analysis and code
navigation, with which users can improve and understand their software
development process. GitHub has built Semantic, a program analysis tool capable
of parsing and extracting detailed information from source code. The
development of Semantic has relied extensively on the functional programming
literature; this paper describes how connections to academic research inspired
and informed the development of an industrial-scale program analysis toolkit.
