IdentityServer - An open-source, standards-compliant, and flexible OpenID Connect and OAuth 2.x framework for ASP.NET Core
1Password - 1Password can create strong, unique passwords for you, remember them, and restore them, all directly in your web browser.
DotNetOpenAuth - DotNetOpenAuth is a free-to-use compiled library that comes with the real support to your site visitor to login with the help of openIDs via getting control of the ASP.NET control onto the page.
Dashlane - Dashlane is a secure way to bypass tedious logins, forms, and purchases online. Save all of your information and save time in your online transactions.
Okta Workforce Identity - Okta Workforce Identity is utility software for enterprises that provides a new way of work that enable your employees, contractors, and partners to use technology on any device.
Lastpass - LastPass is an online password manager and form filler that makes web browsing easier and more secure.