yEd - yEd is a free desktop application to quickly create, import, edit, and automatically arrange diagrams. It runs on Windows, Mac OS X, and Unix/Linux.
Puppet Enterprise - Get started with Puppet Enterprise, or upgrade or expand.
draw.io - Online diagramming application
Packer - Packer is an open-source software for creating identical machine images from a single source configuration.
LucidChart - LucidChart is the missing link in online productivity suites. LucidChart allows users to create, collaborate on, and publish attractive flowcharts and other diagrams from a web browser.
Terraform - Tool for building, changing, and versioning infrastructure safely and efficiently.