[uj6re]

open source: keycloak connect2id dex gluu

closed source self hosted: adfs

hosted: okta (auth0) google microsoft github amazon

these are just the ones that were viable 2 years ago

[mooreds]

Another closed source option, which can be self-hosted or used as a SaaS: FusionAuth (my employer). It also has a full featured plan which is free if you self host and is available via docker, etc.

[orra]

Thanks, although connect2id doesn't look open source.

[vemgar]

also open source: Authentik

[orphea]

also open source: zitadel

[mffap]

https://github.com/zitadel/zitadel