  We give an overview of the current status of perturbative QCD factorization
theorems in processes that involve transverse momentum dependent (TMD) parton
distribution functions (PDFs) and fragmentation functions (FF). We enumerate
those cases where TMD-factorization is well-established, and mention cases
where it is likely to fail. We discuss recent progress in the implementation of
specific TMD-factorization calculations, including the implementation of
evolution. We also give examples of hard part calculations. We end by
discussing future strategies for the implementation of TMD-factorization in
phenomenological applications.
