SAML client library written in Go (golang)
SAML is the successful OASIS standard for cloud based single sign on (SSO). SAML allows for companies that maintain a security infrastructure internally to allow using that same set of credentials via a safe, secure mechanism with externally hosted services.
For instance, New Relic allows you to configure a saml provider (https://newrelic.com/docs/subscriptions/saml-service-providers) so you can maintain your own credentials instead of using New Relic's.
Ping Identity has a nice video for SAML here: https://www.pingidentity.com/resource-center/Introduction-to-SAML-Video.cfm