µLibrary is a new library for Nintendo DS. Basically, it is meant to use the 3D GPU to create nice 2D games very easily, using a different approach than existing libraries (quite similar to OSLib).
The 3D GPU provides additional effects over the 2D GPU, like full transparency with alpha channel (objects can blend amongst them), a larger number of sprites (up to 1536 instead of 128), no zoom or rotation limit (2x with the 2D GPU), a larger limit for the sprite size (2048x2048 instead of 64x64). It is also possible to draw primitives like lines, rectangles, etc. allowing nice effects like in Yoshi's island for example
µLibrary also provides a low level layer and is open to the hardware. You can also mix 2D and 3D in a single project.
The problem of using the 3D GPU is clear: you can only use one screen at a time, or 2 screens but at 30 fps. However, µLibrary is fully compatible with PALib and you can use it to handle the second screen at 60 fps. It's a good solution if you do not plan to use the second screen intensively: displaying a BG with some sprites and get the stylus state could be enough, and you can concentrate on the main screen which is driven by µLibrary.
