Cake Issues is free to use, improve, contribute and distribute. Source code is available on GitHub under MIT license.
Cake Issues provides aliases to create reports from the parsed issues. There's a generic reporting addin which allows to create reports using out-of-the-box or custom Razor templates and an addin for creating SARIF compatible files.
The addins are built in a modular architecture and are providing different extension points which allow you to easily enhance it for supporting additional analyzers, linters, report formats and pull request systems.