Citrix Systems Inc. has released a 64-bit version of its flagship product, which it says will enable users to significantly increase server workloads and reduce hardware needs.

The Citrix Presentation Server 4.0 for Microsoft Windows Server 2003 x64 edition will allow users to run 64- and 32-bit applications on a server. Those applications, regardless of whether they are 64-bit, will be accessible to any device now used as a Citrix client, including thin clients and desktops.

If the system is installed on a two-processor, dual-core server running x86-based processors capable of either 64- or 32-bit, it should support approximately twice the number of users of a two-processor machine, Citrix officials said. That"s because it offers improved memory and application performance, said Anthony Ricco, senior director of platform marketing at Citrix.

The software will also allow IT managers to move gradually to a 64-bit application environment because it can run either 64- or 32-bit applications on the same server, said Ricco.

Gartner Inc. analyst Mark Margevicius called 64-bit "a wonderful thing for server-based computing" because of the generally high costs of moving to server-based systems.

Server-based computing requires a network infrastructure to support it, as well as redundant servers and licensing costs, making it capital-intensive, said Margevicius.

Pricing begins at US$290 per concurrent users, said Fort Lauderdale, Fla.-based Citrix.