Note that OSeMOSYS works with LEAP as does NEMO. OseMOSYS and NEMO are optimization modeling frameworks. Neither has any user interface. LEAP provides a front and back end UI for managing data, creating scenarios, visualizing results etc. as well as modeling capabilities in areas not covered by OSeMOSYS such as demand-side modeling, simulation modeling, non-energy sector modeling and modeling of the health impacts arising from emissions. In general, we now recommend using NEMO with LEAP instead of OSeMOSYS as it supports various new capabilities such as more flexible sub-annual time-slicing and energy storage. NEMO also support a much wider range of solvers.