  Over the last year, the amount of research in hierarchical planning has
increased, leading to significant improvements in the performance of planners.
However, the research is diverging and planners are somewhat hard to compare
against each other. This is mostly caused by the fact that there is no standard
set of benchmark domains, nor even a common description language for
hierarchical planning problems. As a consequence, the available planners
support a widely varying set of features and (almost) none of them can solve
(or even parse) any problem developed for another planner. With this paper, we
propose to create a new track for the IPC in which hierarchical planners will
compete. This competition will result in a standardised description language,
broader support for core features of that language among planners, a set of
benchmark problems, a means to fairly and objectively compare HTN planners, and
for new challenges for planners.
