What are some alternatives?
When comparing Zabbix and Site24x7, you can also consider the following products
Datadog - See metrics from all of your apps, tools & services in one place with Datadog's cloud monitoring as a service solution. Try it for free.
LogicMonitor - LogicMonitor is the SaaS performance monitoring platform for the world's best IT teams. Deploy Fast, Monitor More, Improve Ops.
Nagios - Complete monitoring and alerting for servers, switches, applications, and services
Pulseway - Pulseway changes the enterprise monitoring and management game with its mobile management solution.
Icinga - Icinga is a fork of Nagios and is backward compatible.
Pingdom - With website monitoring from Pingdom you will be the first to know when your website is down. No installation required. 30-day free trial.