Nitro.NET 
Nitro.NET supplies a set of class libraries to read/write the contents of Nintendo DS ROMS ("Games") into easily consumable .NET components. The intent is to allow developers to easily construct tools for home-brew development on the NDS platform.
The library is developed based on the limited information I can find on the internet.
Note: This project is a re-implementation of a project I had worked on previously and at this time does not support all the functionality of the older project. This notice will be removed as soon as this project has caught up.