Assimilation System Management Suite
The Assimilation Suite discovers systems, services, network connections, configuration and dependencies, IP and MAC addresses. This all goes into a continually updated graph-based configuration management database (CMDB). This is then compared and scored against best practices, services and servers are monitored - all with near-zero configuration - in a way that scales to hundreds of thousands of servers. It also provides visualization tools, APIs for sending alerts to humans and other systems, and a variety of canned reports (queries) to aid in securing and managing systems, hooking into ChatOps, and creating plans for triaging your security issues
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Basebox-Packer
A comprehensive set of Packer definitions. It has quite a collection of 64 bit and 32 bit images for Vagrant VirtualBox and VMWare. A good place to learn Packer definitions.
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Boxstarter
Repeatable, reboot resilient windows environment installations made easy using Chocolatey packages. When its time to repave either bare metal or virtualized instances, locally or on a remote machine, Boxstarter can automate both trivial and highly complex installations. Compatible with all Windows versions from Windows 7/2008 R2 forward.
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Eucalyptus
An open source software for building Amazon EC2-compatible private and hybrid cloud platforms
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Monit
An open source utility for managing and monitoring processes, programs, files, directories and filesystems
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