Jaguar, Apple's new version of Mac OS X, packs a much bigger upgrade punch than its 10.2 version number suggests. Part of that punch is the price: Jaguar costs £99 (inc. VAT), and you only get an upgrade discount if you bought a new Mac without version 10.2 on or after 17 July. But its slightly improved interface, powerful new networking tools, three new applications, and better performance and stability finally bring Mac OS X's potential to fruition. If you bought OS X 10.1 before 17 July and you're not looking for networking support, £99 is too much to pay. But if you're a business user or you have a cross-platform home network, take a serious look at Jaguar.