The high-energy community has devoted a significant effort over the past several years to devise more efficient strategies for discovering new physics at the world's premier particle colliders. In recent approaches, experimental analyses of new theoretical ideas are simulated with the support of multi-purpose matrix element-based generators.
In this talk, I will review some of the most recent developments of a specific parton-level generator, MadGraph/MadEvent, emphasizing two aspects: the generation of quarkonium events and the automatic re-weighting of experimental events with matrix elements. I will also present several applications in order to illustrate the capabilities of these tools, as well as the possibilities they open for further physics studies.