Pinger is an uptime and status monitoring application. It is an open-source implementation of platforms used to create status pages. Unlike other alternatives, Pinger can be deployed to create a standalone status page from a config file as well as a complete platform to manage users, checks, pages, alerts, etc.
All the documentation is available here.
Pinger is being actively developed. Head over to the Contribution section of the documentation for more details on how to set up and hack on the project.
Pinger, all the source code, is released under the MIT License.