Joining Filesystems

I have been thinking about writing a file manager for Genode. This has led me to some questions: Is there already any file manager currently being written? What is the best way of joining multiple filesystems into a single tree? (Or should I be doing something different?) Which libraries/files/functions should I use? I think Boost Filesystems should be ported to Genode at some point, so I might want to use that. How difficult would that be? Or should not add that as a dependency? What's the best way to scan a directory for files and other directories? How much file type detection (and file preview) is safe? Also, I may want to use threading. Are C++11 threads supported?