I will discuss experiments on ultracold atomic gases and high temperature superconductors (SCs) which could probe superconductivity near quantum phase transitions. For cold atom systems, we propose a model of fermionic atoms in a 2D honeycomb lattice which could realize a semimetal-SC transition and discuss the BCS-BEC crossover near such
a transition. For the cuprates, we point out that the underdoped regime is likely influenced by a  SC-insulator quantum phase transition and relate this to Fermi arcs  observed recently in the normal state of these systems.