I've come to the conclusion there is no way I'm going to be able to finish the OpenGL book by the end of the year, as I had hoped. I would like to have the book finished in the first quarter of 2007.
Writing has progressed slower than I thought. I have my facts correct, but I'm having a hard time making the material interesting to read and making clear explanations. I'm frustrated by the slow progress I'm making, but I prefer taking the time to write a good book that helps people instead of rushing a crappy book that doesn't help anyone.