Hi Beman, I tried converting quickbook last night. It was pretty simple, there were a few compile errors but I was able to fix them all by either using the replacement methods or removing 'fs::native' from the constructor. That's for g++ 4.5 on darwin. There were a few compile errors for Clang, I'll look into them if you want. If v2 is default, does that mean that v3 won't be going through our regression tests? Some comments on the parts of the documentation I looked at: http://svn.boost.org/svn/boost/trunk/libs/filesystem/v3/libs/filesystem/doc/... It says 'native_file_string' is now 'file_string', which doesn't exist. According to the reference it's either 'native', or perhaps one of the 'string' methods. I think you should also note in the reference that 'native' returns a reference while the other methods return by copy, it's implicit but easily overlooked. http://svn.boost.org/svn/boost/trunk/libs/filesystem/v3/libs/filesystem/doc/... Since the home page says that cygwin uses the windows api, I assume the description of absolute paths on cygwin is wrong. http://svn.boost.org/svn/boost/trunk/libs/filesystem/v3/libs/filesystem/doc/... I read this to find out about generic and native paths but completely missed that the next section describes how to get the formats from a path object, as I didn't realise what a 'path observer' is. Something along the lines of, 'Methods for accessing these formats are covered in the next section.' would be clearer. It'd also help if you linked back to the section that describes 'tut4'. I jumped into the middle of the tutorial and had to look back to find out what it did. Daniel