Google has produced an updated version of its desktop search. It will now be able to search the full text of pdf files and the metadata of multi-media files.

Until now, the product could only index the names of such files. But the new version will indexing the entire content, including such data as song and artist names in music files.

The search is also now considered a finished product. "We've taken the product out of beta because now we have all the file types and features that were high on the list of user requests," said product manager Nikhil Bhatla, adding that by removing the beta tag, Google is hoping more users will feel encouraged to download and install the product.

Competition is fierce among desktop search - a market that only really starting existing a few months ago. It is viewed as an important area of the overall search engine market, because increasingly users expect to be able to find information on their PCs in the same way they find information on the Internet.

Although it isn't clear yet how search engine vendors will make money from these tools, most of which are free, it is generally agreed that a user who becomes loyal to a desktop search product is highly likely to extend that loyalty to the tool maker's Internet search engine. In recent years, the market for online ads that search engines serve up with their query results has exploded. However, a big challenge for search engine vendors is to find ways to foster loyalty among their users. Studies have shown users feel little attachment to particular engines.

Google introduced its desktop product in October of last year, joining Lycos and several smaller, niche players, such as Copernic, X1 and Blinkx. However, Google beat big search engine providers such as Microsoft, Ask Jeeves, Yahoo and AOL all of which have subsequently released their own test versions of desktop search tools. Yahoo partnered with X1 and AOL with Copernic for their respective desktop search entries.

Other improvements in the Google desktop tool, which is free, are support for the Mozilla's Firefox browser and Thunderbird e-mail application and for AOL's Netscape browser and e-mail application. Previously, the product supported only Internet Explorer browser and Outlook/Outlook Express.

Google is also releasing an API tool kit for developers to create plug-in applications that extend the product. The software development kit is available at http://desktop.google.com, along with documentation, sample code and some plug-ins that have already been built.

One such plug-in lets users index instant messaging (IM) conversations from Cerulean Studios' popular Trillian IM application; the original version of the product only indexed IM sessions from AOL's AIM service. Another plug-in available Monday will be one to search the metadata of music files acquired from Apple's iTunes music store.

Soon, a third-party developer will create a plug-in that, using speech-to-text technology, will allow the product to transcribe the content of audio and video files and make it searchable, thus deepening the indexing capabilities of those files beyond metadata, Bhatla said.

Although this desktop search tool is designed for use by consumers, Google continues to work hard at developing a version that is appropriate for the workplace, he said. However, this new version does have one enterprise feature: It recognises Microsoft group policy parameters on a PC and cancels its own installation if the parameters state that the Google desktop tool can't be run on that machine.

It is also available for the first time in Chinese and Korean.