The ATT&CK Navigator is designed to provide basic navigation and annotation of ATT&CK matrices, something that people are already doing today in tools like Excel. We've designed it to be simple and generic - you can use the Navigator to visualize your defensive coverage, your red/blue team planning, the frequency of detected techniques or anything else you want to do. The Navigator doesn't care - it just allows you to manipulate the cells in the matrix (color coding, adding a comment, assigning a numerical value, etc.). We thought having a simple tool that everyone could use to visualize the matrix would help make it easy to use ATT&CK.
The principal feature of the Navigator is the ability for users to define layers - custom views of the ATT&CK knowledge base - e.g. showing just those techniques for a particular platform or highlighting techniques a specific adversary has been known to use. Layers can be created interactively within the Navigator or generated programmatically and then visualized via the Navigator.
For more information see the ATT&CK Navigator release announcement
Open Source Repository
The ATT&CK Navigator was released as an open source project and is available for use as a standalone tool or integrated within another application.