The tool that wakes you up when the server crashes. Known for its reliable phone/SMS alerting and complex escalation policies. However, the pricing model is steep, forcing companies to limit who is 'on-call' to save money, which hurts reliability.

Atlassian's on-call management tool. It excels at deeply integrating with Jira tickets. However, recent pricing changes often require bundling it with Jira Service Management, forcing you to pay for a full ITSM desk just to get SMS alerts.