MEGA includes many sophisticated methods and tools for phylogenomics and phylomedicine. It is licensed as proprietary freeware. The project for developing this software was initiated by the leadership of Masatoshi Nei in his laboratory at the Pennsylvania State University in collaboration with his graduate student Sudhir Kumar and postdoctoral fellow Koichiro Tamura. MEGA version 2 (MEGA2), which was coauthored by an additional investigator Ingrid Jakobson, was released in 2001. All the computer programs and the readme files of this version could be sent electronically due to advances in computer technology. MEGA has been updated and expanded several times and currently all these versions are available from the MEGA website. The latest release, MEGA7, has been optimized for use on 64-bit computing systems. MEGA is in two versions. A graphical user interface is available as a native Microsoft Windows program. A command line version, MEGA-Computing Core (MEGA-CC), is available for native cross-platform operation. The method is widely used and cited.