On not really related note the rate of downloads for my diffyqs notes is rising in the last week. I think I’m detecting the start of semester for many US colleges. I bet it will increase even more once the fall semester/quarter starts everywhere.
Now on related note, I’m typing up my notes for math 444 here, which is basic real analysis. So I’m writing another textbook: really baby analysis. Take baby Rudin and make it a lot less ambitious. If I were really crazy I could also take my sort of typed notes from last semester’s basic linear algebra and make those into a textbook … some other time I think, I didn’t really like the syllabus for that course, so if I were to make a textbook there it would differ more from the course here at UIUC.