Fluentd - Fluentd is a cross platform open source data collection solution originally developed at Treasure Data.
HackMD - Fast and flexible, real-time collaborative markdown, inspired by Hackpad.
Splunk - Splunk's operational intelligence platform helps unearth intelligent insights from machine data.
Documize - Enterprise-grade wiki and knowledge management platform
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.
ReadTheDocs - Spend your time on writing high quality documentation, not on the tools to make your documentation work.