Microsoft last week made available for free its Services for Unix software, which helps integrate Unix and Windows, and supports migrations of Unix applications to the Microsoft platform.Microsoft\u00a0last week made available for free its Services for Unix software, which helps integrate Unix and Windows, and supports migrations of Unix applications to the Microsoft platform.The software, which will be demonstrated this week at LinuxWorld, is seen as a key tool in Microsoft's battle against Unix and\u00a0Linux. Microsoft has felt pressure from the growing popularity of Linux and losing potential Unix converts to the open source platform. The company says it hopes the free integration software will be just another reason to stay on the Windows platform.Previously, Microsoft charged $99 for the software, but Services for Unix 3.5 now is available as a free download from the company's Web site. Version 3.5 adds support for Windows XP Professional and Windows Server 2003 in addition to the existing support for Windows 2000. However, Microsoft is dropping support for Windows NT 4.0 workstation and server, according to company officials.Services for Unix 3.5 provides the tools and subsystems to integrate Unix or Linux with the Windows platform. It also lets users support the migration of Unix\u00a0applications\u00a0to Windows."Free is a smart strategy," says Laura DiDio, an analyst with The Yankee Group. "Microsoft is trying to make good and trying to make better with its customers. I'm impressed with what they are doing. They have learned from their mistakes, and they don't want to repeat the sins of past years." One of those sins, DiDio says, was changes in the company's software licensing program, which alienated users.Services for Unix 3.5 includes performance improvements for Network File System (NFS) and Network Information Services (NIS), which are both de facto Unix standards."The POSIX Subsystem File I\/O performance is within 10% of the native Win32 file system performance," says Dennis Oldroyd, director of marketing for the Windows server group at Microsoft.Microsoft also has improved the ability to recompile Unix and Linux applications to run on Windows by adding support for PThreads, or Portable Operating System Interface for Unix threads, which lets multiple tasks run concurrently within an application.Microsoft also has enhanced integration with Active Directory, which will let users manage NIS domains from the Microsoft directory. The integration, along with applications from third-party vendors, will help Microsoft flesh out its emerging identity management strategy.One such vendor,\u00a0Vintela, has upgraded its Vintela Authentication Services (VAS), which uses Services for Unix 3.5. The VAS software runs on Unix servers and workstations, and uses\u00a0Kerberos\u00a0or\u00a0Lightweight Directory Access Protocol\u00a0for authentication instead of NIS."Ours is a NIS migration strategy; you don't run NIS on your network any longer," says Matt Peterson, CTO for Vintela. "We are the Holy Grail of identity management. People want integration not synchronization [between Unix and Windows]."Microsoft's Oldroyd says Services for Unix will remain a separate product and there are no immediate plans to bundle it or build it into Windows even though Microsoft has the right to do so under a licensing agreement it signed with\u00a0The SCO Group\u00a0last year.