Quoted from: https://www.sei.org/projects-and-tools/tools/leap-long-range-energy-alternatives-planning-system/ 

LEAP is a transparent and user-friendly tool for energy and climate mitigation planning that has been adopted by thousands of organizations in nearly 190 countries worldwide, including government agencies, academics, nonprofits, consulting companies and energy utilities. It can be used at a wide range of scales, from cities and states to national, regional and even global applications. At least 37 countries used LEAP to help develop their Nationally Determined Contributions (NDCs) submitted to the UNFCCC’s Paris climate conference in 2015, and LEAP is rapidly becoming the de facto standard for countries undertaking integrated resource planning and greenhouse gas mitigation assessments, especially in the developing world.

LEAP and its associated training materials and documentation are available free of charge to qualified academic, governmental and nonprofit organizations based in the low and middle income countries and to students worldwide. Consulting companies, utilities and other businesses can access LEAP through affordable licensing arrangements.

LEAP is distributed and supported by SEI through the LEAP web site, which has more than 36,000 members worldwide. Along with developing and supporting LEAP, SEI also develops LEAP-based scenario studies, helping policy-makers and planners explore their options to meet future energy needs, mitigate climate change, and shift to a low-carbon development pathway.