The Plastic File System
Links

User-Mode filesystems using LD_PRELOAD:

• AVFS
• VirtualFS
• AccessFS
• Freesoft Preload Libraries

User-Mode filesystems using a server process:

• UserVFS (was "podfuk")
• Traps and Pitfalls: Practical Problems in System Call Interposition Based Security Tools

Other neat hacks using LD_PRELOAD:

• ZLibc
• Date Shift