AWStats - AWStats is a Open Source Web Analytics software written in Perl.
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.
Coralogix - Coralogix is a machine learning powered log analytics solution aimed to solve the problem of unmanageable log data.
AppDynamics - Get real-time insight from your apps using Application Performance Management—how they’re being used, how they’re performing, where they need help.
Modlogan - Modlogan is a modular logfile analyzer able to parse FTP, Web Server and Squid logs.
Zabbix - Track, record, alert and visualize performance and availability of IT resources