A Windows network that operates completely standalone and doesn't need to interact with other computing platforms is rare. Far more common are heterogeneous installations in which Windows networks run side-by-side with UNIX and Linux networks. Windows Services for UNIX (SFU) bridges some large gaps in Windows-UNIX interoperability. Despite the product's name, most of SFU's features apply equally to Linux. Licenses for earlier releases of SFU were $99 for each installed system, but SFU 3.5 is a free download for Windows customers. In this month's Top 10, I list the most important features in SFU 3.5. You can find more information about SFU 3.5 at http://www.microsoft.com/windows/sfu.

10. Telnet—For cross-platform administration, SFU provides Telnet Server and Telnet Client support. SFU has a Windows-based version of the Telnet server and client as well as an Interix version. The Windows version supports NTLM authentication to allow remote logon without sending a plaintext user ID and password across the network.

9. UNIX shells—To facilitate migration of UNIX administration skills to the Windows environment, SFU provides two UNIX command shells: the C shell and the Korn shell. Both shells work on Windows just as they do on a UNIX host. A bash shell is also available as a free download from http://www.interopsystems.com/tools.

8. UNIX command-line utilities—SFU supports more than 350 commonly used UNIX commands and utilities, including grep, awk, gcc, make, emacs, vi, and sendmail.

7. Scriptable management—For graphical management, SFU uses Microsoft Management Console (MMC) snap-ins. In addition, it provides several command-line management options as well as scriptable management through Windows Management Instrumentation (WMI).

6. User Name Mapping—SFU's User Name Mapping service provides bidirectional name mapping between UNIX users and Windows users and groups. The service supports one-to-one mappings as well as many-to-one mappings that let multiple UNIX user IDs map to a single Windows user and vice versa.

5. Interix UNIX application runtime—SFU's Interix UNIX application runtime support runs as a native Windows subsystem, providing an environment that behaves as UNIX applications expect and a full set of APIs, compilers, and utilities for creating and migrating UNIX applications.

4. Perl 5.6.1 and ActivePerl—Perl is a powerful scripting language that works well in both Windows and UNIX environments. SFU 3.5 includes Perl 5.6.1 and ActiveState's ActivePerl and supports common management scripts for both Windows and UNIX systems.

3. Password synchronization—To address the difficulty of keeping up with password changes in a heterogeneous environment, SFU provides bidirectional password synchronization capability. Administrators can restrict password changes to specific users, and SFU's Password Synchronization feature uses the Triple DES (3DES) algorithm to encrypt passwords that are sent across the network.

2. Server for NIS—Server for NIS (Network Information System) stores UNIX users, groups, and hosts in Active Directory (AD), thus letting UNIX users authenticate against AD and letting Windows administrators manage UNIX users in the same ways that they manage Windows users. Server for NIS also keeps Windows and UNIX user passwords in sync.

1. NFS support—A key feature of SFU is its NFS support. SFU supports NFS client, server, and gateway functionality. Server for NFS lets UNIX clients connect to Windows file shares; Client for NFS lets Windows systems access UNIX files and directories. Gateway for NFS provides NFS-resource access to downstream clients that don't run the Client for NFS software.