Long overdue, here is, as promised, the source code to WhineCube. It is provided as-is, in hopes that it will be useful to other emulator authors.
It's licensed under the terms of the GNU GPL, version 2, except for a few parts which are in the public domain.
I haven't worked on WhineCube for some time now, and I don't expect I shall take it up again in the foreseeable future. Still, if anyone have questions about the source code, I'll be happy to answer them, either here or in my IRC channel, #whinecube on Efnet.