StatCounter - StatCounter is a simple but powerful real-time web analytics service that helps you track, analyse and understand your visitors so you can make good decisions to become more successful online.
Fluentd - Fluentd is a cross platform open source data collection solution originally developed at Treasure Data.
AFSAnalytics - AFSAnalytics.
Splunk - Splunk's operational intelligence platform helps unearth intelligent insights from machine data.
Woopra - Track your customers' web and mobile activity, forms, emails, support tickets and more, all in one place with customer analytics. Analyze and take action.
Graylog - Graylog is an open source log management platform for collecting, indexing, and analyzing both structured and unstructured data.