Onepiecefs is a project mainly written in PYTHON and SHELL, it's free.
build example in mac osx
o install MacFUSE-2.0.3,2 http://code.google.com/p/macfuse/
o install fuse-python pip install fuse-python
o when error try sudo touch /usr/include/osreldate.h pip install fuse-python rm /usr/include/osreldate.h
o install tornado pip install tornado
o install urlgrabber pip install urlgrabber
usage
start opfsd.py
$ python opfsd.py
mount opfs
$ python opfsmount.py