3DS:Menuhax

menuhax refers to a series of exploits in the HOME Menu released between 2015 and 2016. It was mostly superseded by arm9loaderhax. There is a "new version of menuhax" that works on newer versions called menuhax67 that can install the homebrew launcher to the home icon on the top left of the HOME menu, but it's just an entrypoint for an exploit like (as an example) HBL-USM and it requires another userland exploit to install it. Not recommended at all.

Upgrading to boot9strap
See the page 3DS:Migrate from menuhax to upgrade a console to boot9strap.

How it works
menuhax consists of 4 exploits: themehax, shufflehax, sdiconhax, and bossbannerhax. More details can be found on.