GitHub repository: nagyist/kratos
Primary language: Go
Description: Next-gen identity server (think Auth0, Okta, Firebase) with Ory-hardened authentication, MFA, FIDO2, TOTP, WebAuthn, profile management, identity schemas, social sign in, registration, account recovery, passwordless. Golang, headless, API-only - without templating or theming headaches. Available as a cloud service.