Tools are software that improve Chef's ecosystem. An example of a tool is Cookstyle. Cookstyle is a Ruby gem that analyzes the code of a Chef Infra cookbook. Most tools are open source and available on GitHub.
Add the tools and plugins that you have created to Supermarket to share them with the community.
There are various types of tools, each serving a slightly different purpose. If your tool does not fall into one of the types below, open a GitHub issue requesting to add that type.