The term packages is ambiguous, and so is modularization.
Free Pascal inherits the unit system for modularization from Turbo Pascal, but apparently you mean a different kind of modularization. The namespace gimmick is later and not that interesting.
If you mean a modularization on a multiple binaries (DLL/BPL+EXE) level, that is currently hard or impossible. The Lazarus/GUI packages are basically just project files for build purposes, and not anything dynamically linkable.
So that means it is basically C level DLLs or multiple EXE's with IPC.
For some background you can also read
https://wiki.freepascal.org/packages