Samba -

SAMBA is a system which allows systems to communicate using SMB or CIFS
protocols (used by MS Windows for network communication) thus permitting
sharing either way of printers and disks with such systems. (The VMS
client is however a utility, not a mountable filesystem.) 

Included are a port of Samba 2.2.8 for VMS and a very recent release of
Samba 3.0 source code (for those wanting to port the latest and greatest Samba
code).