Thanks for the note about carriage returns. I already use a little program to assemble the files from several locations before zipping, so I'll add this. I'm assuming Unix-style newlines are best.
I haven't figured out how to get along with "possible loss of data" warnings. I'll have to revisit the issue in more depth. I run into problems finding some benefit which outweighs their cost.
Argh, regarding the DMC and IRQ, I had just removed all that from the latest version of Nes_Snd_Emu, since it wasn't necessary for playing NSFs and the APU IRQ code wasn't completely working. I'll put it back in and post an update in a few days.
Other than those three things, everything is great! Thank you so much for making the handiest library EVER.
If you're writing a GameBoy emulator any time soon, I just spend the last two days writing a GameBoy sound emulator with almost identical design style as the NES sound emulator :) It started as an experiment with applying Blip_Buffer to gbsplay and ended up with a complete rewrite (and 30x performance increase).
These are my first library-releasing experiences so the feedback is useful.