Super Mario 64 DS Editor (SM64DSe) is an editor for SM64DS originally created by Mega-Mario/StapleButter that I've been updating and maintaining for the past year and a half.
Screenshots:




Main Features:
- Import new course models and collision maps from OBJ or DAE models
- Full control over placement of objects, enemies, Stars etc.
- Import and export level minimaps
- Import and export to/from the game's graphics format
- Texture editor for models
- Support for editing animated textures, both in levels eg. scrolling water and character/enemy models eg. blinking
- Text editor
- Additional patches manager for applying small ASM hacks with several useful patches included
- Export any game model to OBJ or DAE, including character models with full joints information
- [WIP] Export rigged and animated models from the game's native format to DAE
Upcoming Features:
- Importing rigged and animated models to the game's native format from DAE
You can download the latest version from here
More information and updates at kuribo64.net
I've also made a very short demo that replaces Mario with Deku Link to show the editor's ability.

Credit for the Deku Link model goes to Zerox from Spriters' Resource: http://www.models-resource.com/nintendo_64/lozmm/model/520/
Video
Download
Screenshots:
Main Features:
- Import new course models and collision maps from OBJ or DAE models
- Full control over placement of objects, enemies, Stars etc.
- Import and export level minimaps
- Import and export to/from the game's graphics format
- Texture editor for models
- Support for editing animated textures, both in levels eg. scrolling water and character/enemy models eg. blinking
- Text editor
- Additional patches manager for applying small ASM hacks with several useful patches included
- Export any game model to OBJ or DAE, including character models with full joints information
- [WIP] Export rigged and animated models from the game's native format to DAE
Upcoming Features:
- Importing rigged and animated models to the game's native format from DAE
You can download the latest version from here
More information and updates at kuribo64.net
I've also made a very short demo that replaces Mario with Deku Link to show the editor's ability.
Credit for the Deku Link model goes to Zerox from Spriters' Resource: http://www.models-resource.com/nintendo_64/lozmm/model/520/
Video
Download