This work extends the ARES framework for NNLL resummations: automating calculations via the use of fixed-order event generators, and, extending the ARES method to multi-jet observables. We extend the ARES method to multi-jet observables in electron-positron annihilation, and we use this extension to perform the first NNLL resummation of the D-parameter, a three-jet event-shape. We introduce a new method to interface resummations to fixed-order event generators. Utilising this new method we interface jet-veto resummations with the fixed-order code MCFM. The result is a new code capable of resumming jet-veto effects in all processes that proceed via a colour-singlet, and completely differential in leptonic final states. We use the code to resum jet-veto effects in WW final states at the Large Hadron Collider, and place constraints on the unique dimension-six operator coupling gluons to the Higgs field.