GitHub, Inc. is a provider of Internet hosting for software development and version control using Git. It offers the distributed version control and source code management (SCM) functionality of Git, plus its own features.
The GitHub front site and social media for their update information system is using Alliance No.1 and Blimone (both by Degarism Studio). Alliance No.1 is used both for running texts and display typography. Blimone appears for Github ReadME podcast promotion in its Medium Inktrap style, alongside text in Alliance No.2.
The key figures on the homepage are specified to use the operating system’s monospaced UI font, and hence will look different from user to user. The font shown in the images appears to be DejaVu Sans Mono (or Menlo).