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
Consul
Consul makes it simple for services to register themselves and to discover other services via a DNS or HTTP interface. Register external services such as SaaS providers as well
linux windows osx open-source service-discovery go monitoring
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
Nomad
Nomad is a lightweight workload orchestrator. It offers client instance scaling as well as workload scaling.
linux windows osx open-source virt orchestration go
SaltStack
Salt is a powerful and different approach to infrastructure management, by focusing on high speed communications between large number of systems, and can perform orchestration, remote code execution and much more.
linux windows osx open-source commercial config-mgmt provisioning orchestration python
Serf
Serf is a service discovery and orchestration tool which is highly decentralized, highly available, fault tolerant, cross platform and extremely lightweight.
linux windows osx open-source orchestration go