According to some of the ill-informed opinion in the IT market, UNIX is dead and Microsoft Windows NT is the future.

UNIX, Windows, DOS, OS/2 and Windows NT are all common names but people do not know which system to choose.Never before has the IT business moved so fast or been in such a state of technical and commercial turmoil.

Investigation into Windows NT and how it is likely to be taken up in different market areas are not simple issues.So what is the fuss all about, and what is Windows NT anyway? To understand the answer, it is necessary to understand a little of the background to the operating systems debate.

Operating systems - the software that lets us talk meaningfully to the hardware - come in two general flavours: 'proprietary' and 'open'.

Both of these terms are confusing and often misused.The general definition of a proprietary operating system is one written by a manufacturer for their hardware, eg IBM AS400 or DEC VAX.

This operating system contains many features that add value by using the special functions the manufacturer has included in the hardware.

Proprietary operating systems date from the time when markets were won by technical differentiation.The trouble with technical differentiation is that it is very divisive.

While this is a good way of protecting market share as a manufacturer, it is bad news for end users and software houses which have to write lots of different versions if they want to sell on a number of platforms.Enter the white knight of 'open' systems.

The concept here is that if a set of standards in the development of operating systems is used, then in theory the software should be portable from one platform to another.The key component in the emergence of open systems was the development of UNIX from AT&T.

UNIX became the central component of many of the open systems initiatives, and even non-UNIX operating systems started to use many UNIX concepts and interfaces.

The problem is that open systems are not so much 'open' as 'ajar'.

There has been a great proliferation of versions.

While UNIX started life as a simple system with a lot of power, it has prompted dozens of versions.

Some of these are very different, a reflection of the influence on standards of high levels of innovation.To combat this, standard interfaces have been developed for applications development.

Though many of these are a lot looser than one might like, they reduce - rather than eliminate - the problems of moving software and data from one system to another.

Many 'open' systems are now not based on UNIX but simply support a set of open systems standards.The idea of supporting standard interfaces is one of the central themes in Microsoft's NT (New Technology) operating system.

Microsoft was responsible for DOS and then Windows - DOS is the operating system; Windows sits on top providing a powerful level of graphical user interface.Unfortunately, Windows and DOS are tied to the Intel range of microprocessors.

They were also designed as a single-user operating system.

This left Microsoft out in the cold when it came to the multi-user systems.

It had trouble competing with UNIX when it came to the strategically important parts of the system or in the support of multi-user applications.IBM and Microsoft tried to solve this problem with the development of OS/2.

This failed to take off as well as either UNIX or DOS/Windows partly because, like DOS/Windows, OS/2 is still tied to Intel based platforms, and partly because of the lack of applications vendors willing to commit fully to OS/2.Windows NT tries to solve many of these issues in one sweep by supporting a number of interfaces that allow the running of applications originally designed for DOS, Windows 3.1, OS/2, the Posix 1013 programming standard for UNIX, and native Win32 Windows NT applications.

It also offers full portability to a range of hardware platforms - Intel, DEC, Alpha, MIPS, etc; proper support for multi-user applications; an architecture designed to last for a long time; and the ability to cope with technology changes at a number of levels.Despite the name, Windows NT is not just another version of Microsoft Windows or DOS.

It is a completely new operating system - though from first appearances it could be mistaken for Windows 3.1.

It seems ideal: an operating system which brings everything together in a multi-user environment, with a workstation and server version as well.But it is not enough simply to buy Windows NT and hope your troubles are over.

There are many issues which need addressing first which are routed in the applications and the standards themselves.Many legal applications vendors and systems integrators have little experience of Windows NT.

However, the trend of adopting Windows NT in the financial community is ahead of many other markets.

It is true to say that most applications for Windows NT have been ported from other operating systems rather than written for the native facilities.

Where the por t has yet to take place there is need for caution; the standards are loose enough to ensure that the port may not be as simple as running up the application on a new box.Taking a UNIX application to Windows NT can be a complex exercise.

Even DOS and Windows applications may need work, depending on the version of the operating system they run on and how they are written.

In addition, to make use of Windows NT one would generally want to configure it in a client-server arrangement.

This means having part of the application and/or data on the server computer and part on the client computer, thereby apportioning work and data to appropriate resources.

While this is fairly straightforward, it is often beyond the capabilities of many applications without some level of re-engineering of their code.The next issue is support.

Applications vendors, systems integrators and consultants need to understand how to use NT.

Few people have the competence to do this; Windows NT skills are in short supply at the moment.

Many organisations supplying the market have their hands full simply coping with DOS to Windows conversions, or moving from one version of UNIX to another.

The following points provide advice on whether to follow the NT route or not.-- Look at what you have.

Get a clear view - with expert help if needed - of your operating system and hardware.

Understand exactly what they are, and then assess when this will need replacement.

If you are running UNIX then find out if the applications were written to be Posix compliant.

They probably were not, particularly in the legal market.

Find out if you will be running more than one version of UNIX.

If you are, the first step is to move to a single version for all applications.-- Talk to your applications vendor.

If you have a PC network using either Novell or Microsoft based networking, find out what their plans are regarding Windows NT.

Ask if they can demonstrate it to you, and what experience they have of porting to and using the platform's hardware and software.

Then find out how many other people are running the Windows NT version of the application.-- If you are planning your future IT strategy, first decide which applications are required.

Talk to the applications vendors and find out which fit your business needs.

Then look to see how and if NT fits into your plans: its main benefit to you should be as a method of integrating a lot of disparate applications onto a single, homogeneous platform while allowing you a greater degree of vendor independence.Microsoft Windows NT is the most innovative operating system ever developed.

It is a bold and aggressive attempt to sort out many of the issues that have confused and complicated the IT market over the past 20 or so years.

Microsoft is likely to provide a de facto standard system for much of the small end of the market with Windows NT, but it will be two to three years at least before many legal applications are available and properly supported by the vendors.UNIX is threatened by Windows NT.

Novell, which owns UNIX, has already responded with some of its own counter measures to the issue of support for applications from other operating systems.

UNIX is far from dead, and such a big community of applications is not going to move overnight.

However, NT has forced to the surface the issues of support of applications and porting that the industry has not previously addressed well.

Its introduction is putting a lot of pressure on the UNIX community.

The outcome will be two fold: applications will be ported over to Windows NT in time, an d changes will be made to UNIX to make it more competitive.

On balance, this has to be good news for the legal IT market.In time, applications will be made available and supported on the system.

First to move will be DOS-based applications, then Windows and OS/2 applications.

UNIX applications will take a little longer.

On one platform, all of these applications will be capable of running efficiently, removing the need for many different operating systems in one office.

The applications you need will, finally, all be available on one platform.To limit the use of Windows NT to integration of applications from different platforms is to ignore much of its power.

The full capabilities can really be demonstrated by the development of applications in native Win32 mode on the system.

With its powerful Windows interface and true multi-user facilities, Windows NT offers much that UNIX could not at the same price.Few applications companies are developing native Windows NT applications today.

This is not surprising.

Apart from the shortage of skills, the rate of innovation from Microsoft on Windows and Windows NT is difficult to keep up with for the average software developer.

Windows NT is an option to watch.

If you have the resources, it is well worth getting a copy and starting to build your own in-house expertise.

When the applications eventually become supported on Windows NT you should then be ready to move with ease.Microsoft has started another phase of its revolution with this offering.

Already it has democratised the computing world with DOS and Windows, now it is raising the stakes and it is the end user that will benefit.

In the legal market, Windows NT will offer facilities such as true resilience of the operating system that are absent today in DOS, but essential for a non-stop environment to service client data.

Windows NT is the best option for the DOS and Windows 3.1 users of today who need a more robust system with the minimum of disruption.

By making the choice, one is effectively buying protection for the future, something the insurance industry knows all about.