CMake knows about the packages using the MeVisLab PackageScanner. It especially extends the CMake modules path to the cmake directory found in any package.

associated tools like ToolRunner know about packages.

a MeVisLab module, accessible with ctx in scripting, knows its package: ctx.package().packageIdentifier().

MDL knows about packages using MLAB_PackageGroup_PackageName variables.

MLABPackageManager provides package information to Python scripting.

wizards use packages as their target.

installers know about packages (SWITCH_PACKAGE, etc.).