Luma3DS is a program (Custom Firmware) to patch the system software of (New) Nintendo 3DS handheld consoles “on the fly”, adding features (such as per-game language settings and debugging capabilities for developers) and removing restrictions enforced by Nintendo (such as the region lock). It also allows you to run unauthorized (“homebrew”) content by removing signature checks.

For details on setup, usage and features please visit the Wiki:

Developer Page: