Disruptions in laboratory fusion experiments, solar and stellar flares, and substorms in the Earth's magnetosphere are driven by the explosive release of magnetic energy during magnetic reconnection. A major scientific challenge to understanding reconnection has been the multi-scale nature of the problem: a narrow boundary layer, the
dissipation region, breaks field lines and controls the release of energy in a macroscale system. Significant progress has been made on understanding the role of non-MHD waves and slow-mode shocks in driving fast reconnection and its explosive onset in large systems. The role of turbulence in the dissipations region and
associated anomalous resistivity has been explored. Observations and models are increasing suggesting that reconnection in large systems is a multi-x-line, multi-island phenomenon, which greatly increases
computational challenges to understanding magnetic dissipation rates and particle acceleration.