Prometheus - An open-source systems monitoring and alerting toolkit.
CrashPlan - CrashPlan for Small Business backup software offers the best way to back up and store business & enterprise data securely - offsite, onsite & online in the Cloud.
Nagios - Complete monitoring and alerting for servers, switches, applications, and services
ManageWP - ManageWP is a service for bloggers, site owners and web based companies helping them manage multiple WordPress sites from one dashboard.
StatsD - Simple daemon for easy stats aggregation.
Backblaze - Backblaze's remote backup automatically backs up your data to our secure datacenter.