Apple's new Xserve rackmount server is aimed at getting large companies to think of Apple as synonymous with as IBM, Dell and Sun when they're looking for a network or internet server. But although you can order an Xserve now and get hold of it in June, you might have to wait until the end of the year for the final piece of the puzzle.

Apple already has a serious network operating system in Mac OS X Server. Originally released back in 2000 and based on the same powerful Unix kernel as Mac OS X, it includes the Apache web server, QuickTime Streaming Server and Web Objects application server.

There's a new version, codenamed Jaguar Server, due late this summer. And unlike most Unix systems you'll be able to upgrade to it rather than having to install from scratch, but Apple has had problems selling the server OS to companies because it hasn't had the hardware to go with it. At the launch Steve Jobs joked that Mac users talking about the enterprise are more likely to mean Star Trek than serious computing systems.

Xserve could change that because it's a powerful system designed specifically for OS X Server. One or two 1GHz G4 processors with 2MB DDR (double data rate) L3 cache and dual gigabit ethernet ports make it fast; four ATA/100 drives in the hot-swappable bays that pop out of the front give you up to 480GB of disk space; and the sleek aluminium case takes up just one slot in a rack.

Fill a whole cabinet with Xserves and you could have 84 processors and 20TB (terabytes) of storage; at £2,055 (£2,741 for the dual-processor machine) Xserve isn't the cheapest option but you do save a lot on the cost of Windows 2000 licenses.

Apple has chosen some unusual hardware: the Xserve is the first server at this price to use fast DDR memory and the ATA drives are just as fast as the SCSI drives you usually see in servers but they're smaller and cheaper.

Most users will control the Xserve remotely, either using Apple's own Server Admin and Server Monitor software which, claims Apple's Phil Schiller, "works a lot like iTunes", or a standard SNMP network monitoring package like HP's OpenView. So the graphics card is a basic PCI card from ATI but you can remove the PCI adaptor and fit an AGP card if you want more powerful graphics.

What you don't get are the duplicate power supplies and other backup components in some servers: Apple claims companies would rather replace parts when they need to.

The Xserve is certainly designed to be easy to open and easy to service: the whole thing slides open like a drawer and you can pop out the drive bays by pressing on the front. You can also lock the case and the drive bays and get a warning when they're opened as well as detailed alerts (by email or pager) if anything goes wrong with the system. Apple is promising 24/7 technical support and kits of spare parts you can fit yourself.

And by the end of 2002 Apple will have Xserve Raid, a 14-bay storage system with up to 1.68TB of disk space and duplicates of every component. Impressive as the Xserve is on its own, we think companies wanting to run vital applications will need the backup of unit like this. If you'd rather not wait, you can put a SCSI card in the Xserve and connect to a Raid array from another supplier.

Another key piece in the puzzle is enterprise software: Sybase and Oracle have both announced version of their database software for OS X Server.

Apple has spent a lot of time talking to the companies who'd buy Xserve and is claiming to be "humble" about moving into the server market. This is certainly a more coherent strategy than previous Apple attempts to produce high-end servers, which Steve Jobs described as "a dream when Apple was in a coma" and it could be real competition for Microsoft as well as Sun.