Monitoring Infrastructure and application (performance) monitoring (APM) AppOptics (formerly Librato) Bugsnag Datadog Graylog Healthchecks Host Tracker Hosted Graphite LogicMonitor Loggly Monitor.us Nagios NetData New Relic Ping Test (keycdn) Pingdom Sentry Service Uptime SimpleOps Stackify UpTrends Wormly System monitoring bashtop MRTG Monit ctop btop htop Linux Dash Service status dashboards StatusHub