PDDL was originally conceived and constructed as a lingua franca for the International Planning Competition. PDDL2.1 embodies a set of extensions intended to support the expression of something closer to real planning problems. This objective has only been partially achieved, due in large part to a deliberate focus on not moving too far from classical planning models and solution methods.
@article{arxiv.1110.2730,
title = {Imperfect Match: PDDL 2.1 and Real Applications},
author = {M. S. Boddy},
journal= {arXiv preprint arXiv:1110.2730},
year = {2011}
}