ConDep
ConDep is a open source infrastructure configuration and deployment DSL (Domain Specific Language) specifically targeted to (but not limited to) the Windows Server platform. If your familiar with tools like Chef and Puppet, ConDep does very much the same, but with native support for Windows.
windows open-source ci provisioning config-mgmt net
InfluxDB
InfluxDB is a time series, metrics, and analytics database. It’s written in Go and has no external dependencies. InfluxDB is targeted at use cases for DevOps, metrics, sensor data, and real-time analytics.
linux open-source monitoring go metrics
KairosDB
KairosDB is a fast distributed scalable time series database written on top of Cassandra. RESTful JSON-based query/results. Includes flot-based visualization.
linux windows osx open-source metrics visualization java cassandra
Prometheus
Prometheus is an open-source systems monitoring and alerting toolkit built at SoundCloud.
linux open-source go metrics monitoring