  Results on open charm and beauty production and on the search for top
production in high-energy electron-proton collisions at HERA are reviewed. This
includes a discussion of relevant theoretical aspects, a summary of the
available measurements and measurement techniques, and their impact on improved
understanding of QCD and its parameters, such as parton density functions and
charm- and beauty-quark masses. The impact of these results on measurements at
the LHC and elsewhere is also addressed.
