jocopoco proposes version 1.0.0.4 of "TronDS", nintendo 3DS for windows emulator. TronDS isn't the only existing 3DS emulator, however it is the only one to be compiled and distributed. It is capable of running some homebrew but remains nevertheless very buggy.
Tronds 1.0.0.4
Fixed a bug launching CLR on Windows Vista and above.
Fixed bugs on VFPU emulation.
Fixed bugs in vertex shaders emulation.
Fixed bugs in textures management.
Add support for GSP Service.