A California startup is about to launch an upgrade to its free Internet service that lets you download a suite of compact office applications but save data and files on a hosted server.

ThinkFree Office applications from ThinkFree.com intentionally mimic the widely used Microsoft Office applications in features and appearance.

But ThinkFree users can, from any computer, download the applications as needed over the Internet, work offline, and then reconnect to move documents, spreadsheets, and presentations to a dedicated "cyberfolder" - a network drive with 25MB of disk space for each user.

Microsoft and Sun Microsystems are readying similar offerings. Microsoft is adapting Microsoft Office, and Sun, StarOffice so the programs can be accessed via the Web.

The ThinkFree applications, including a word processor, spreadsheet, and presentation graphics, are written in Java and, with a click on a Web link, install automatically on the client.

The complete group of programs needs about 6.5MB of storage and an additional 2MB for the Java graphics libraries, called Swing. The word processor alone is just under 1.5MB.

Because it's a true set of applications, the ThinkFree suite is highly interactive, with items such as drop-down windows and menus.

By contrast, pure HTML applications lack these capabilities and have to connect over the Net to the server each time a screen is changed.

"There's a lot of processing power on the PC, so why not use it?" asks Richard Buchanan, vice president of marketing at ThinkFree.com.

Buchanan says the ThinkFree programs have up to 90 percent of the features found in Microsoft Office. ThinkFree documents, spreadsheets, and presentation graphics are fully compatible with their Microsoft counterparts, he says.

You register for the free service and receive a user name and password. You log on via a Web browser, then link to begin the initial download. Once the applications install, you can log off and click on an icon to activate them.

ThinkFree, like the Hotmail and Yahoo sites, will make money from advertisers and partners on its Web site.

The upcoming release of ThinkFree, due 4 July, relies on the older Java 1.0 specification. The software is being revamped using Java2, which includes a way of creating reusable components, called JavaBeans.