Software Heritage are mirroring code from GitHub and other places:<p><a href="https://www.softwareheritage.org/" rel="nofollow">https://www.softwareheritage.org/</a><p>Also ArchiveTeam have a project to archive GitHub repos when requested, to archive.org:<p><a href="https://wiki.archiveteam.org/index.php/ArchiveTeam" rel="nofollow">https://wiki.archiveteam.org/index.php/ArchiveTeam</a>