Which ssh server does GitHub use?

[cryptexctl]

I wanted to know this out of interest, but I was greeted by this banner on netcat:

lain@navi ~> nc github.com 22
SSH-2.0-88f9acd9

And this conclusion is quite incomprehensible, because SSH-2.0 = protocol version, and 88f9acd9 = commit used as the server version (?) and it doesn't make it any clear whether it's OpenSSH or anything else...

debug1: Local version string SSH-2.0-OpenSSH_9.7
debug1: Remote protocol version 2.0, remote software version 88f9acd9
debug1: compat_banner: no match: 88f9acd9
debug1: Authenticating to github.com:22 as 'git'