DS2x86 by Patrick Aalto is a PC emulator for Nintendo DS. It's purpose is to allow you to run old DOS games on your Nintendo DS game console. DS2x86 is a port of DSx86 port using the SuperCard DSTwo's MIPS processor, therefor it will just run with such a card. Read more about DS2x86 v0.22 (DOS emu for NDS)
DSx86 is a PC/DOS emulator for Nintendo DS written by Patrick Aalto. It's purpose is to allow you to run old DOS games on your Nintendo DS game console. Some of the older games run quite good and bring back memories. Read more about DSx86 v0.37 (DOS emu for NDS)
DSDoom is a port of Doom by wintermute to the Nintendo DS based off the PrBoom source tree because of its purity and portability. Original game data is required and does not come with the download pack. The author accepts donations! Read more about DSDoom v1.2.0 (NDS Engine Port)
Pocket Island DS by MJaoune is not (yet?) a game. There are little guys which you can annoy with your stylus and there are few options to change the weather. Read more about Pocket Island DS v0.91 (NDS misc)
Jayenkai is one of those restless game coders, who always has something in his pocket. While not limited on the platforms he develops, he brings his game "Sheep Goes Left" to the Nintendo DS. Guide your sheep always left, but avoid obstacles. Sounds easy, is easy, but only in the first few levels. Read more about Sheep Goes Left (Beta) (NDS Game)