Amazon Cognito vs sso: What are the differences?
Amazon Cognito: Securely manage and synchronize app data for your users across their mobile devices. You can create unique identities for your users through a number of public login providers (Amazon, Facebook, and Google) and also support unauthenticated guests. You can save app data locally on users’ devices allowing your applications to work even when the devices are offline; sso: Buzzfeed's single-sign-on authentication proxy. The authentication and authorization system BuzzFeed developed to provide a secure, single sign-on experience for access to the many internal web apps used by our employees.
Amazon Cognito and sso can be categorized as "User Management and Authentication" tools.
sso is an open source tool with 2.11K GitHub stars and 109 GitHub forks. Here's a link to sso's open source repository on GitHub.