I’ve only run across one thing that might be promising: The MacFUSE/OS X Fuse project. This is a system involving a kernel extension, libraries and tools designed to support third-party file systems.
Various communities have developed many different file system drivers for use with macFUSE.
Although not included with macFUSE, I found an HFS file system driver for use with macFUSE.
IMPORTANT: I have never used any of the above tools. I have no idea if they work as advertised and I don’t plan on trying them because the idea of installing kernel extensions like this scares me. If you want to try it, I recommend testing it on a Mac you are OK with wiping (or in a virtual machine) in case it should fail catastrophically.