For those interested in the blog posts and other technical information about the engine they shared with the public, check out:
https://books.ourmachinery.com/
http://web.archive.org/web/20220529231010/https://ourmachine...
https://books.ourmachinery.com/
http://web.archive.org/web/20220529231010/https://ourmachine...
Probably deleted
And if you accurate and patient enough, I think, you can manually copy latest state of repo
http://web.archive.org/web/20220801082043/https://github.com...