Reggie! is an easy-to-use and full-featured level editor for New Super Mario Bros. Wii, created by Treeki and Tempus.
Features
  • Terrain editing
  • Sprite editing, with over 1,200 properties available
  • Entrance editing
  • Image display for over 200 sprites
  • Background options, with image previews
  • Zone options
  • Zoom, Grid and Autosave
  • Settable level information
  • Resizable and interactive level overview
  • Location editing
  • Path editing
  • Cross-platform (Windows, Linux, macOS)
  • Open-source (GNU General Public License v2)
  • Riivolution loader for custom levels with original discs
Screenshots (click to enlarge)
Screenshot of World 3-3 in Reggie!
World 6-1 screenshot World 7-3 screenshot World 8-Doomship screenshot
World 5-1 screenshot World 6-2 screenshot World 7-6 screenshot
Download
The latest release for Windows, Ubuntu, and macOS can be found on this page.
Old versions of Reggie (before 2021) are known to have security risks, so using a recent version is strongly recommended.

For help and support, please visit the NSMBW Hacking Depot Discord server.
To dump the required files for Reggie! from your game disc, please use the Reggie! Dumper app.
Current GitHub project (for developers): Reggie-Updated