Customers who have purchased Automation Platform and who develop their own plug-ins for the CODESYS development system.
Automation Platform uses its own proprietary implementation for dependency injection, and it turns out to be rather hard to develop unit tests for plug-ins which require external dependencies.
Therefore the APUnitTestFramework is a software component which mimics the CODESYS environment during the runtime of a unit test, and which enables resetting the environment to its initial state (which is not a feature in the real Automation Platform at all, for various reasons).
You must adapt the references in the solution and the csproj files to your individual installation of the Automation Platform SDK, as well as the postbuild step. After that, building and installing the APUnitTestFramework.plugin.dll should be no problem for experienced Automation Platform developers.