devkitARM is the toolchain everybody uses to create great homebrew which I guess could be considered a particularly significant contribution to the Nintendo DS scene.
http://devkitpro.org/wiki/devkitARM
(sorry about the realWinterMute thing, someone already nabbed that nick)
http://devkitpro.org/wiki/devkitARM
(sorry about the realWinterMute thing, someone already nabbed that nick)