Cachet - Cachet is a free, open source status page for your API, service or company. Built with all of the features that you'd expect from a status page.
StatusPage.io - StatusPage.io is the best way for web infrastructure, developer API, and SaaS companies to get set up with their very own status page in minutes. Integrate public metrics and allow your customers to subscribe to be updated automatically.
cState - 🔥 Free & open source under MIT!
Trendy 404s - A set of creative templates for your 404s
Status.io - Status.io is a platform for system status pages and status notifications. Companies rely on Status.io to track outages, schedule planned maintenances, broadcast status notifications, and much more; and their customers love the transparency.
FourZeroFour - Showcase of the best error pages on the web.