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
Instrumental
Instrumental is a real-time, high-scale application and server monitoring tool with intelligent alerts, a powerful query language, and free development accounts.
linux windows oxs free metrics commercial metrics monitoring visualization php ruby python net java nodejs
testssl.sh
A command-line tool which checks a server's service on any port for the support of TLS/SSL ciphers, protocols as well as some cryptographic flaws. It's designed to provide clear output for your "is this good or bad" decision.
linux osx open-source security shell
Zipkin
A distributed request tracking system, useful for micro-service and distributed architectures written in Scala
linux windows osx open-source monitoring scala