Bret Truchan has just put up the source code for his awesome CellsDS on github at:
https://github.com/clone45/cellsds
I want to make a tiny tweak to allow more than 8 sequencer blocks. However, I can't compile the code because it was built for older versions of DevkitARM/PAlib/libnds which don't seem to be anywhere on the web (around r21 of DevkitARM I believe, and whatever libnds and PAlib were current then)
If anyone has the right versions of these to compile the code, or can make it work some other way, I'd love to hear from you.