Pierre Buyle is a user on octodon.social. You can follow them or interact with them if you have an account anywhere in the fediverse.
If you don't, you can sign up here.
If you are looking for an alternative to GitHub and want more options than Gitlab there is also Gogs. If you just need Git hosting without a web UI, pull request, etc. but not self hosted, check Keybase.io.
