Sun Microsystems is looking to advance its utility-computing strategy through last week's acquisition of Tarantella Inc., a provider of software used by desktops and other client devices to access and manage data over the Web. Sun expects the transaction, worth about $25 million, to close by September.

Tarantella's Secure Global Desktop software is designed to provide secure access to server-based applications running on Linux, Unix, Microsoft Windows, mainframe, and midrange operating systems. Like competitor Citrix Systems Inc., Tarantella's business revolves around providing thin-client devices with access to enterprise apps and information residing on back-end servers.

Although Tarantella's market presence has been on the decline, Secure Global Desktop is used by companies that espouse the server-based computing model that Sun has promoted. Competitors such as Dell, Hewlett-Packard, and IBM, all of which have or have had large PC businesses, depend on Microsoft's Windows desktop operating system.

With Tarantella's technology, applications aren't stored or run locally on a PC. Users access applications via a Web browser by authenticating themselves to a server running Tarantella's software. Once users are authenticated, an HTML-based desktop lets them access only applications they have permission to use.

The acquisition of Tarantella ultimately will make it easier for Sun customers to deploy desktops that run either open-source StarOffice applications or those from Microsoft, says David Friedlander, a Forrester Research senior analyst. The move also puts Sun's R&D and marketing engines behind technology developed by Tarantella, which had unsuccessfully tried to compete with Citrix in the $2 billion market for server-based computing software, Friedlander says.

Tarantella began as Santa Cruz Operation Inc., which in August 2000 sold its Unix server software and services divisions, as well as UnixWare and OpenServer operating systems, to Caldera Systems Inc. Santa Cruz Operations renamed itself Tarantella and focused on Web-enabled terminal-services applications.