Avfs: a true on-access anti-virus file system that incrementally scans files and prevents infected data from being committed to disk. Avfs is a stackable file system and therefore can add virus detection to any other file system
Dazuko: This project provides a kernel module, which provides 3d-party applications an interface for file access control. You can use it with Clamuko
Famuko: Famuko is a on-access scanner based on libfam and working in userspace.
samba-vscan: samba-vscan provides on-access scanning of Samba shares with ClamAV