Zabbix - Track, record, alert and visualize performance and availability of IT resources
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.
Observium - Observium
IdentityServer - An open-source, standards-compliant, and flexible OpenID Connect and OAuth 2.x framework for ASP.NET Core
Nagios - Complete monitoring and alerting for servers, switches, applications, and services
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.