Packer is a tool for creating identical machine images for multiple platforms from a single source configuration.
Terraform enables you to safely and predictably create, change, and improve infrastructure. It is an open source tool that codifies APIs into declarative configuration files that can be shared amongst team members, treated as code, edited, reviewed, and versioned.
Concourse is a container-based continuous thing-doer written in Go and Elm.
Terragrunt is a thin wrapper for Terraform that provides extra tools for working with multiple Terraform modules.