Around that time I went down the rabbit hole of "what if I wanted to write a filesystem for Windows NT?" It turns out that, aside from network redirectors, Microsoft didn't think this was something people ought to do very often. The people at Atria (which got bought by Rational) who were working on ClearCase were pioneers, and they bought a source license from Microsoft to be able to do it. The result was that there was a lot of information from them on a mailing list about how do implement a filesystem. However, it was mostly incomprehensible to me, because kernel programming on NT is quite different from what one would expect coming from other backgrounds, including Windows 95, OS/2, and Linux.
