Creating a virtual file system

[Jeff Schwab]

Bryan Olson wrote:
> Jeff Schwab wrote:
>  > You don't have to pay Microsoft to develop a Windows-compatible
>  > filesystem.  See http://ubiqx.org/cifs/.
> 
> That's a different usage of "filesystem" than what is at issue
> here.

I agree that you & I are probably discussing different things, but I 
think this is exactly what the OP was seeking.  He said:

 > I'm working on a project to implement a simple cross-platform file
 > sharing protocol (using Python) that is similar to HTTP, and I
 > have to write a GUI for Windows and Linux.

Sure sounds like CIFS to me.

 > My question is: How do I implement a virtual partition that acts
 > like a real file-system and is compleatly transparent to other
 > programs?  Should I make a virtual file allocation table for a
 > FAT32 partition or simulate an NTFS? Or even further: How do I
 > create a junction (or a hard link) to it in "My network places" or
 > in "Entire Network"?

CIFS is the canonical way to make resources show up in Network 
Neighborhood.  The OP even said:

 > If there are tools that could help me but written in C or C++,
 > please let me know, I'll compile them to Python modules.

Free, open source CIFS implementations already exist in C and Java.

I'm guessing that to you (as to many of us) a filesystem is usually a 
way of mapping blocks on a device to parts of files, but I don't think 
that's what the OP actually wanted.